Repositionable and removable stents

ABSTRACT

An illustrative endoluminal implant having an elongated tubular member. The elongated tubular member having a stent and a retrieval suture interwoven with the stent. The retrieval suture including a first suture loop extending about a circumference of the stent and adjacent to a suture retrieval loop and a second suture loop extending about a circumference of the stent and longitudinally spaced from the first suture loop. The first and second suture loops coupled via one or more interconnecting segments. At least one of the first or second suture loops has an arc length of less than 270° of the circumference of the stent.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. § 119 ofU.S. Provisional Application No. 62/735,651, filed Sep. 24, 2018, theentire disclosure of which is hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure relates generally to methods and apparatuses forrepositioning and/or removing stents or implants. More particularly, thedisclosure relates to structures for collapsing repositionable and/orremovable stents or implants.

BACKGROUND

Implantable stents are devices that are placed in a tubular bodystructure, such as a blood vessel, esophagus, trachea, biliary tract,colon, intestine, stomach or body cavity, to provide support and tomaintain the structure open. These devices are manufactured by any oneof a variety of different manufacturing methods and may be usedaccording to any one of a variety of methods. Of the known medicaldevices, delivery systems, and methods, each has certain advantages anddisadvantages. There is an ongoing need to provide alternative medicaldevices and delivery/retrieval devices as well as alternative methodsfor manufacturing and using medical devices and delivery/retrievaldevices.

SUMMARY

This disclosure is directed to several alternative designs, materials,methods of manufacturing medical device structures and associated usesthereof, such as stents for preventing leaks after an anastomosissurgery and/or treating various gastro-intestinal, digestive, or otherailments.

In a first example, an implant may comprise an elongated tubular member.The elongated tubular member may comprise a stent having a proximal endregion, a distal end region, and a circumference. A retrieval suture isinterwoven with the stent. The retrieval suture may include a firstsuture loop extending circumferentially around the stent and adjacent toa suture retrieval loop and a second suture loop extendingcircumferentially around the stent and longitudinally spaced from thefirst suture loop. The first and second suture loops may be coupled viaone or more interconnecting segments. At least one of the first orsecond suture loops may have an arc length of 270° or less of thecircumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the first and second suture loops may each have an arc lengthof 270° or less of the circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the at least one of the first or second suture loops may havean arc length of 180° or less of the circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the first and second suture loops may each have an arc lengthof 180° or less of the circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the first suture loop may be a discontinuous loop comprisingtwo or more circumferential segments of the retrieval suture separatedby the one or more interconnecting longitudinal segments.

Alternatively or additionally to any of the examples above, in anotherexample, the retrieval suture may be a single unitary structure.

Alternatively or additionally to any of the examples above, in anotherexample, the stent may include a first outer diameter adjacent theproximal end region and a second smaller outer diameter adjacent thedistal end region.

Alternatively or additionally to any of the examples above, in anotherexample, the first suture loop may be positioned adjacent to theproximal end region and the second suture loop may be positionedadjacent to the distal end region.

Alternatively or additionally to any of the examples above, in anotherexample, a force exerted on the retrieval suture loop may be configuredto partially collapse the stent adjacent to the second suture loop.

Alternatively or additionally to any of the examples above, in anotherexample, once an outer diameter of the stent adjacent to the secondsuture loop is at least partially collapsed, the force exerted on theretrieval suture loop may be configured to collapse the stent adjacentto the first suture loop.

Alternatively or additionally to any of the examples above, in anotherexample, the retrieval suture may further comprise a third suture loopextending circumferentially around the stent and longitudinally spacedfrom the second suture loop, the second and third suture loops coupledvia one or more interconnecting segments.

Alternatively or additionally to any of the examples above, in anotherexample, the elongated tubular member may further comprise a flexiblesleeve extending distally from the distal end region of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the retrieval suture may further comprise a third suture loopextending about a circumference of the flexible sleeve andlongitudinally spaced from the second suture loop, the second and thirdsuture loops coupled via one or more interconnecting segments.

Alternatively or additionally to any of the examples above, in anotherexample, a force exerted on the retrieval suture loop may be configuredto partially collapse the flexible sleeve adjacent to the third sutureloop.

Alternatively or additionally to any of the examples above, in anotherexample, once an outer diameter of the flexible sleeve adjacent to thethird suture loop is at least partially collapsed, the force exerted onthe retrieval suture loop may be configured to sequentially collapse thestent adjacent to the second suture loop followed by the stent adjacentto the first suture loop.

In another example, an implant may comprise an elongated tubular member.The elongated tubular member may comprise a stent having a proximal endand a distal end and a retrieval suture interwoven with the stent. Theretrieval suture may comprise a first segment extendingcircumferentially between a first circumferential location and a secondcircumferential location, a second segment extending longitudinallybetween the second circumferential location and a third circumferentiallocation, a third segment extending circumferentially between the thirdcircumferential location and a fourth circumferential location, a fourthsegment extending longitudinally between the fourth circumferentiallocation and a fifth circumferential location, and a fifth segmentextending circumferentially between the fifth circumferential locationand a sixth circumferential location. The first, second, fifth, andsixth circumferential locations may be at a first longitudinal distancefrom the proximal end of the stent and the third and fourthcircumferential locations may be at a second longitudinal distance,different from the first longitudinal distance, from the proximal end ofthe stent. The first and fifth segments may together form adiscontinuous first suture loop and the third segment may form a secondsuture loop. At least one of the first or second suture loops may havean arc length of 270° or less of the circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the at least one of the first or second suture loops may havean arc length of 180° or less of the circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the retrieval suture may be a single unitary structure.

In another example, an implant may comprise an elongated tubular member.The elongate tubular member may comprise a stent having a proximal endregion and a distal end region, the stent including a first outerdiameter adjacent the proximal end region and a second smaller outerdiameter adjacent the distal end region, a flexible sleeve extendingdistally from the distal end region of the stent, and a retrieval sutureinterwoven with the stent, the retrieval suture including a first sutureloop extending about a circumference of the stent and adjacent to asuture retrieval loop, a second suture loop extending about acircumference of the stent and longitudinally spaced from the firstsuture loop, and a third suture loop extending about a circumference ofthe flexible sleeve and longitudinally spaced from the second sutureloop, the first and second suture loops coupled via one or moreinterconnecting segments and the second and third suture loops coupledvia one or more interconnecting segments. At least one of the first,second, or third suture loops may have an arc length of 270° or less ofthe circumference of the stent.

Alternatively or additionally to any of the examples above, in anotherexample, the at least one of the first, second, or third suture loopsmay have an arc length of 180° or less of the circumference of thestent.

Alternatively or additionally to any of the examples above, in anotherexample, the retrieval suture may be a single unitary structure.

Alternatively or additionally to any of the examples above, in anotherexample, the first suture loop and the second suture loop may each beformed of discontinuous segments.

The above summary of exemplary embodiments is not intended to describeeach disclosed embodiment or every implementation of the presentdisclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood in consideration of thefollowing detailed description of various embodiments in connection withthe accompanying drawings, in which:

FIG. 1 is a side view of an illustrative implant with a retrieval suturein a first configuration;

FIG. 2 is a side view of the illustrative implant of FIG. 1 in a firstcollapsed configuration;

FIG. 3 is a side view of the illustrative implant of FIG. 1 in a secondcollapsed configuration;

FIG. 4 is a side view of another illustrative implant with a retrievalsuture in a first configuration;

FIG. 5 is a side view of the illustrative implant of FIG. 4 in a firstcollapsed configuration;

FIG. 6 is a side view of the illustrative implant of FIG. 4 in a secondcollapsed configuration;

FIG. 7A is a side view of another illustrative implant with a retrievalsuture in a first configuration;

FIG. 7B is a top end view of the illustrative implant of FIG. 7A;

FIG. 8A is a side view of the illustrative implant of FIG. 7A in a firstcollapsed configuration;

FIG. 8B is a top end view of the illustrative implant of FIG. 8A;

FIG. 9 is a side view of another illustrative implant with a retrievalsuture in a first configuration;

FIG. 10 is a side view of another illustrative implant with a retrievalsuture in a first configuration;

FIG. 11 is a side view of another illustrative implant with a retrievalsuture in a first configuration; and

FIG. 12 is a side view of another illustrative implant with a retrievalsuture in a first configuration.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit aspects of the invention tothe particular embodiments described. On the contrary, the intention isto cover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

For the following defined terms, these definitions shall be applied,unless a different definition is given in the claims or elsewhere inthis specification.

All numeric values are herein assumed to be modified by the term“about,” whether or not explicitly indicated. The term “about” generallyrefers to a range of numbers that one of skill in the art would considerequivalent to the recited value (i.e., having the same function orresult). In many instances, the terms “about” may be indicative asincluding numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numberswithin that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and5).

Although some suitable dimensions, ranges, and/or values pertaining tovarious components, features and/or specifications are disclosed, one ofthe skill in the art, incited by the present disclosure, wouldunderstand desired dimensions, ranges and/or values may deviate fromthose expressly disclosed.

As used in this specification and the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contentclearly dictates otherwise. As used in this specification and theappended claims, the term “or” is generally employed in its senseincluding “and/or” unless the content clearly dictates otherwise.

For purposes of this disclosure, “proximal” refers to the end closer tothe device operator during use, and “distal” refers to the end furtherfrom the device operator during use.

The following detailed description should be read with reference to thedrawings in which similar elements in different drawings are numberedthe same. The detailed description and the drawings, which are notnecessarily to scale, depict illustrative embodiments and are notintended to limit the scope of the disclosure. The illustrativeembodiments depicted are intended only as exemplary. Selected featuresof any illustrative embodiment may be incorporated into an additionalembodiment unless clearly stated to the contrary.

It is noted that references in the specification to “an embodiment”,“some embodiments”, “other embodiments”, etc., indicate that theembodiment described may include a particular feature, structure, orcharacteristic, but every embodiment may not necessarily include theparticular feature, structure, or characteristic. Moreover, such phrasesare not necessarily referring to the same embodiment. Further, when aparticular feature, structure, or characteristic is described inconnection with one embodiment, it should be understood that suchfeature, structure, or characteristic may also be used connection withother embodiments whether or not explicitly described unless clearedstated to the contrary.

Gastric outlet obstruction (GOO) is the clinical and pathophysiologicalconsequence of any disease process that produces a mechanical impedimentto gastric emptying. The presence of GOO can be classified into diseaseconditions that affect the antrum and pylorus that lead to pyloricdysfunction or disease conditions of the proximal duodenum that restrictefferent flow. Clinical conditions such as peptic ulcer disease (PUD),pyloric stenosis, and gastric polyps represent etiologies for the formerwith pancreatic carcinoma, ampullary cancer, duodenal cancer,cholangiocarcinomas representing etiologies for the latter. In someinstances, GOO may be directly treated through stenting the locationusing gastrointestinal (GI) self-expanding stents. However, placing astent across the pyloric valve may leave the pylorus in a continuallyopen position. However, this may result in gastric leakage into theduodenum. Alternative stent designs are desired to allow the immediateblockage to be opened while allowing for natural pyloric function to beretained.

FIG. 1 illustrates a side view of an illustrative endoluminal implant orstent 10. In some instances, the stent 10 may be formed from anelongated tubular stent frame 12. While the stent 10 is described asgenerally tubular, it is contemplated that the stent 10 may take anycross-sectional shape desired. The stent 10 may have a first, orproximal end 14, a second, or distal end 16, and an intermediate region18 disposed between the first end 14 and the second end 16. The stent 10may include a lumen 20 extending from a first opening adjacent the firstend 14 to a second opening adjacent to the second end 16 to allow forthe passage of food, fluids, etc.

The stent 10 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 10 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 10 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 12 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 12 may be braidedwith one filament. In other embodiments, the stent frame 12 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 12 may beknitted, such as the ULTRAFLEX™ stents made by Boston Scientific Corp.In yet another embodiment, the stent frame 12 may be of a knotted type,such the PRECISION COLONIC™ stents made by Boston Scientific Corp. Instill another embodiment, the stent frame 12 may be laser cut, such asthe EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 10 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 10to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 10 tobe removed with relative ease as well. For example, the stent 10 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 10 may beself-expanding (i.e., configured to automatically radially expand whenunconstrained). In some embodiments, fibers may be used to make thestent 10, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 10 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 10 maybe self-expanding while in other embodiments, the stent 10 may be expandby an expansion device (such as, but not limited to a balloon insertedwithin the lumen 20 of the stent 10). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 10 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 20 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 10may include a first end region 22 proximate the proximal end 14 and asecond end region 24 proximate the second end 16. In some embodiments,the first end region 22 and the second end region 24 may includeretention features or anti-migration flared regions (not explicitlyshown at the second end region 24) having enlarged diameters relative tothe intermediate portion 18. The anti-migration flared regions, whichmay be positioned adjacent to the first end 14 and the second end 16 ofthe stent 10, may be configured to engage an interior portion of thewalls of the esophagus, stomach or other body lumen. In someembodiments, the retention features, or flared regions may have a largerdiameter than the cylindrical intermediate region 18 of the stent 10 toprevent the stent 10 from migrating once placed in the esophagus,stomach, or other body lumen. It is contemplated that a transition fromthe cross-sectional area of the intermediate region 18 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 10 mayhave a uniform diameter from the proximal end 14 to the distal end 16.

It is contemplated that the stent 10 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 10to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 10 tobe removed with relative ease as well. For example, the stent 10 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 10 may beself-expanding or require an external force to expand the stent 10. Insome embodiments, composite filaments may be used to make the stent 10,which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 10 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 10, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 10, or portions thereof, may be biostable.

The implant 10 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 10, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 10 may further include a retrieval suture 26. The suture 26may include a retrieval suture loop 28 which may be configured to begrasped by forceps or other tool during a clinical procedure for stentremoval and or repositioning. In some cases, the retrieval suture loop28 may be formed by tying a knot 30 between, or otherwise coupling(e.g., heat bonding, adhesive, etc.) a first end 32 and a second end 34of the retrieval suture. In other embodiments, the retrieval suture loop28 may be formed at either the first end 32 or the second end 34 of theretrieval suture 26. In such an instance, the end 32, 34 free from theretrieval suture loop 28 may be coupled to the stent 10 or the opposingend 32, 34 of the retrieval suture 26, although this is not required.

The suture 26 may be interwoven with the stent frame 12 at intervalsalong a length of the implant 10 to create a plurality of suture loops36 a, 36 b (collectively, 36). While the illustrative implant 10 isshown and described has having two suture loops 36, it is contemplatedthat the implant 10 may include more than two suture loops 36, asdesired. For example, the implant 10 may include three, four, five, ormore suture loops 36. It is contemplated that the suture loops 36 may bepositioned at regular or even intervals throughout the overall length ofthe implant 10. However, in other embodiments, the suture loops 36 maybe positioned at eccentric or uneven intervals along the length of theimplant 10, as desired. It is contemplated that the suture loops 36 maybe positioned to facilitate retrieval, repositioning, and/or reshapingof the stent 10. For example, in a stent 10 having two or more flared orenlarged regions, as in the AXIOS® stent made and distributed by BostonScientific Corp., a first retrieval suture loop 36 a may be positionedadjacent to the first flare and a second retrieval suture loop 36 b maybe positioned adjacent to the second flare.

In some embodiments, one, two or more, or all of the suture loops 36 mayextend entirely around the circumference (e.g., 360°) of the stent frame12. In other embodiments, one, two or more, or all of the suture loops36 may extend or have an arc length of less than 360° about thecircumference of the stent frame 12. In some embodiments, one or more ofthe suture loops 36 may extend or have an arc length of 350° or less,300° or less, 270° or less, 225° or less, 180° or less, 135° or less,etc. In yet other embodiments, one, two or more, or all of the sutureloops may extend more than 360° about the circumference of the stentframe 12.

The suture loops 36 may be formed from a single unitary suture 26. It iscontemplated that the suture 26 may be interwoven with the stent frame12 such that the suture loops 36 may be constrained in a predeterminedsequential order. In some cases, the proximal loop 36 a may not extendin a continuous loop. Rather, the proximal loop 36 a may be broken intosections by longitudinally extending interconnecting segments 46, 58which extend between the proximal loop 36 a and the distal loop 36 b.

The suture 26 may be interwoven with the stent frame 12 by threading oneof the ends 32, 34 around the proximal end 14 of the implant 10beginning at a first circumferential location 40 and moving (e.g.,threading) in a first direction. In the illustrative example, the suture26 is described as initially being threaded in a clockwise direction.However, the reverse configuration in which the suture is initiallythreaded in a counterclockwise direction is also contemplated. Thesuture 26 may be threaded around about one half of the circumference ofthe implant 10 such that a first segment 44 of the suture 26 extendsbetween the first circumferential location 40 and a secondcircumferential location 42. The first and second circumferentiallocations 40, 42 may be positioned at a similar longitudinal distance(e.g., in a direction extending generally parallel to the longitudinalaxis 50 of the implant 10) from the first end 14 of the implant 10. Insome cases, the suture 26 may be threaded such that it is interwovenwith the stent frame 12 such that a portion of the suture 26 is withinthe lumen 20 of the implant 10 and a portion of the suture 26 ispositioned along an exterior surface of the implant 10 (e.g., such thatit will be in contact with a vessel lumen when the implant 10 isdeployed within the body). At the second circumferential location 42,the suture 26 may be threaded along a length of implant 10 in adirection towards the second end 16 such that a second longitudinallyextending interconnecting segment 46 of the suture 26 extends along alength of the implant 10 in a generally linear direction. The length ofthe second segment 46 of the suture 26 may vary depending on theapplication. For example, some implants 10 may include radiallyextending quills 52 configured to engage a body tissue. The secondsegment 46 may be configured to extend along a length equal to orgreater to a length of the implant 10 including the radially extendingquills 52. This is just one example. Other features of the implant 10,such as, but not limited to, the length of the implant 10 may be used todetermine the length of the second segment 46 of the suture 26.

The second segment 46 of the suture 26 may extend from the secondcircumferential location 42 to a third circumferential location 48. Thesecond circumferential location and the third circumferential location48 may be at similar radial points about the circumference of theimplant 10 but spaced a distance along the length thereof. At the thirdcircumferential location 48, a third segment 54 of the suture 26 may bethreaded radially about the circumference of the implant 10 in a seconddirection (e.g., counterclockwise), opposite to the first direction. Thethird segment 54 may extend between the third circumferential location48 and a fourth circumferential location 56 to form a suture loop 36 b.In some embodiments, the third circumferential location 48 and thefourth circumferential location 56 may be at substantially the sameradial point about the circumference of the implant 10 such that thesuture loop 36 b extends substantially or entirely 360° about thecircumference of the implant 10. In other embodiments the thirdcircumferential location 48 and the fourth circumferential location 56may be radially spaced from one another by, for example, 1° or less, 5°or less, 10° or less, 20° or less, etc.

At the fourth circumferential location 56, the suture 26 may be threadedalong a length of implant 10 in a direction towards the first end 14such that a fourth longitudinally extending interconnecting segment 58of the suture 26 extends along a length of the implant 10 in a directionto the longitudinal axis 50. The length of the fourth segment 58 of thesuture 26 may be about the same length as the second segment 46 of thesuture 26. The fourth segment 58 of the suture 26 may extend between thefourth circumferential location 56 and a fifth circumferential location60. In some cases, the second and/or fourth segments 46, 58 of thesuture may not be interwoven with the stent body 12 but rather extendalong an inner or outer surface of the stent body 12. In someembodiments, the first, second, and fifth circumferential locations 40,42, 60 may be positioned at a similar longitudinal distance (e.g., in adirection extending generally parallel to the longitudinal axis 50 ofthe implant 10) from the first end 14 of the implant 10.

From the fifth circumferential location 60, the suture 26 may bethreaded through the stent body 12 in the first direction (e.g., awayfrom the first segment 44) to form fifth segment 62 of the suture 26.The fifth segment 62 of the suture 26 may be threaded through the stentbody 12 to a sixth circumferential location 64 and/or until it meets thefirst circumferential location 40 (e.g., the starting point) to form theproximal loop 36 a. As described above, the proximal suture loop 36 amay be formed of discontinuous or broken segments 44, 62. In someembodiments, the fifth segment 62 ceases to be interwoven with the stentbody 12 before the suture 26 reaches the first circumferential location40. For example, the first circumferential location 40 may be radiallyspaced from the sixth circumferential location 64 by, for example, 1° orless, 5° or less, 10° or less, 20° or less, etc. A first end 32 of thesuture 26 may extend from the first circumferential location 40 and thesecond end 34 of the suture 26 may extend from the sixth circumferentiallocation 64. The ends 32, 34 of the suture 26 may be tied to form a knot30, glued, and the knot 30 subsequently cured.

It is contemplated that in embodiments where it is desired for thesuture 26 to include suture loops 36 which extend around less than theentire circumference, the suture 26 may be initially threaded about halfof the length of the desired final arc. For example, as will bedescribed in more detail herein, if the finished suture loop 36 is toextend about 180° about the circumference of the implant 10, the suture26 may be initially threaded about 90° around the circumference beforebeing threaded down a length of the implant 10.

To collapse the implant 10, the retrieval suture loop 28, or the firstsuture loop 36 a in the absence of the retrieval suture loop 28, may bepulled or otherwise actuated in a proximal direction. It is contemplatedthat the direction of actuation (e.g., proximal or distal) required toactuate the suture 26 may be dependent on the direction in which thesuture 26 is interwoven with the stent frame 12. As the retrieval sutureloop 28, or the first suture loop 36 a in the absence of the retrievalsuture loop 28, is actuated, the suture loops 36 begin to constrain orreduce the diameter of the implant 10, as shown in FIG. 2, whichillustrates a side view of the illustrative implant 10 during suture 26actuation. The distal or second suture loop 36 b may be constrainedfirst, causing the intermediate portion 18 of the stent body 12 tocollapse or reduce in diameter before the first end 14. Continuedactuation of the retrieval suture loop 28 may cause first end 14 of theimplant 10 to also be reduced in diameter, as shown in FIG. 3. It iscontemplated that the proximal or first suture loop 36 a may not beactuated until the slack is removed from the preceding longitudinallyextending suture loop 36 b and the suture connection links 46, 58 aredrawn taut to apply a force to the next suture loop 36 a. However, thisis not required. In some instances, the connection links 46, 58 may havea length such that the suture loops 36 simultaneously (or approximatelysimultaneously) constrain the implant 10 along its length.

FIG. 4 illustrates a side view of another illustrative endoluminalimplant 100 including a plurality of regions, including, a first orproximal region 102 and a second or distal region 104. While theillustrative implant 100 is shown and described as having two regions102, 104, it is contemplated the implant 100 may include any number ofregions desired, such as, but not limited to, one, two, three, four, ormore. Further, the regions 102, 104 may be any combination of structuresand materials desired. In some cases, the implant 100 may includefeatures (e.g., anti-migration flares, fixation spikes, sutures, etc.)to prevent distal/proximal displacement and/or migration of the implant100, once the implant 100 is positioned and expanded in the body lumen.The implant 100 may include a lumen 106 extending entirely through thelength of the implant 10, such as from a proximal end 108 of the firstregion 102 to a distal end 114 of the second region 104.

In some cases, the first region 102 may take the form of a stent 116including an elongated tubular stent frame 118 defining a lumen. Thestent 116 may be may be entirely, substantially, or partially coveredwith a polymeric covering, such as a coating (not explicitly shown). Thecovering may be disposed on an inner surface and/or outer surface of thestent 116, as desired. When so provided a polymeric covering may reduceor eliminate tissue ingrowth and/or reduce food impaction throughinterstices of the stent 116 into the lumen. It is contemplated thatleaving an outer rim or a portion of the surface uncovered, an area ofhyperplasia can be generated which would create a seal. The stent 116may include regions of differing diameters. For example, the stent 116may include a flared (e.g., enlarged relative to other portions of thestent 116) proximal end region 120 tapering radially inward to aconstant diameter distal end region 122. While not explicitly shown, thestent 116 may include regions increasing diameters (e.g., in the distaldirection), if so desired. The stent frame 118 may be expandable betweena radially collapsed delivery configuration and a radially expandeddeployed configuration. The expanded configuration may secure theimplant 100 at the desired location in a body lumen.

The stent frame 118 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 118 may be knittedwith one filament, as is found, for example, in the ULTRAFLEX™ stents,made and distributed by Boston Scientific Corp. In other embodiments,the stent frame 118 may be braided with several filaments, as is found,for example, in the WALLFLEX®, WALLSTENT®, and POLYFLEX® stents, madeand distributed by Boston Scientific Corp. In yet another embodiment,the stent frame 118 may be of a knotted type, such the PRECISIONCOLONIC™ stents made by Boston Scientific Corp. In still anotherembodiment, the stent frame 118 may be laser cut, such as the EPIC™stents made by Boston Scientific Corp. It is contemplated that the stentframe 118 may be formed having the same structure as one another orhaving a different structure from one another.

It is contemplated that the stent frame 118 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys, and/or polymers, as desired, enabling the stent 116to be expanded into shape when accurately positioned within the body.The material of the stent frame 118 may be the same or different, asdesired. In some instances, the material may be selected to enable thestent 116 to be removed with relative ease as well. For example, thestent frame 118 can be formed from alloys such as, but not limited to,nitinol and ELGILOY®. Depending the on material selected forconstruction, the stent 116 may be self-expanding (i.e., configured toautomatically radially expand when unconstrained). In some embodiments,fibers may be used to make the stent frame 118, which may be compositefibers, for example, having an outer shell made of nitinol having aplatinum core. It is further contemplated the stent frame 118 may beformed from polymers including, but not limited to, polyethyleneterephthalate (PET). In some embodiments, the stent 116 may beself-expanding while in other embodiments, the stent 116 may be expandedby an expansion device (such as, but not limited to a balloon insertedwithin a lumen 106 of the implant 100). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath).

The stent 116 may include a one-way valve, such as an elastomeric slitvalve or duck bill valve, positioned within the lumen 106 thereof toprevent retrograde flow of fluid or other material, such asgastrointestinal fluids.

In some cases, the second region 104 may take the form of a flexiblesleeve 124. The flexible sleeve 124 may extend between a proximal end112 adjacent to the distal end 110 of the stent 116 and a distal end 114extending distally therefrom. For example, the sleeve 124 may beconnected, affixed, or secured to the distal end region 122 of the firstor stent 116 adjacent to a proximal end region 112 of the sleeve 124. Insome cases, the sleeve 124 may overlap a portion or all of the stent116. In some instances, the sleeve 124 may be devoid of any structuralcomponents tending to hold the lumen 106 through the sleeve 124 open,thus allowing the sleeve 124 to collapse inward upon itself whensubjected to an external force (such as, but not limited to a pyloricvalve) thus closing off the lumen 106. In some embodiments, the sleeve124 may extend partially, substantially, or all of the length of theimplant 100 and cover all other portions (exterior surface and/orinterior surface) of the implant 100, including the stent 116. Saiddifferently, while the regions 102, 104 have been described as a stent116 or a sleeve 124, each region may include one or both of a framestructure and flexible sleeve structure. The sleeve 124 may be securedto the stent 116 by an adhesive or other methods known in the art,including by not limited to thermal methods, mechanical methods, etc.

The sleeve 124 may have an elongated, tubular shape defining a lumen.The lumen of the stent 116 and the flexible sleeve 124 may be fluidlyconnected to form the lumen 106 of the implant 100. It is contemplatedthat one or more of the regions 102, 104 of the implant 100 may includemore than one lumen, as desired. The sleeve 124 may be a thin flexiblemembrane that readily collapses on itself. For example, the sleeve 124may be configured to collapse upon itself under the applied radial forceexerted by a natural valve or sphincter when the implant 100 is deployedin a body lumen having a natural valve or sphincter. However, the sleeve124 may be provided with a radial support to hold it in the expandedconfiguration. Some examples and discussion of illustrative supports maybe found in Patent Application No. 62/419,707, filed on Nov. 9, 11616,titled DEPLOYABLE SLEEVES AND RELATED METHODS, the disclosure of whichis incorporated herein by reference.

The sleeve 124 may include one or more of the following polymermaterials: polyethylene, polypropylene, polystyrene, polyester,biosorbable plastics (e.g., polylactic acid), polycarbonate, polyvinylchloride, polyacrylate, acrylate, polysulfone, polyetheretherketone,thermoplastic elastomers, thermoset elastomers (e.g., silicone),poly-p-xylylene (parylene), flouropolymers (e.g.,polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF),poly(vinylidene fluoride-co-hexafluoropropylene) (PVDFHFP)), bioplastics(e.g., cellulose acetate). The sleeve 124 may additionally oralternatively include one or more of: polyurethane and its copolymers,ethylene vinyl-acetate, polyethylene terephthalate (PET), polyolefins,cellulosics, polyamides, acrylonitrile butadiene styrene copolymers,styrene isoprene butadiene (SIBS) block copolymers, acrylics,poly(glycolide-lactide) copolymer, Tecothane, PEBAX,poly(γ-caprolactone), poly(γ-hydroxybutyrate), polydioxanone,poly(γ-ethyl glutamate), polyiminocarbonates, poly(ortho ester), and/orpolyanhydrides. Blends of the above polymers may also be employed, suchas, but not limited to ChronoFlex®, manufactured by AdvanSourceBiomaterials, based in Wilmington, Mass., a family of biodurablearomatic polycarbonate based thermoplastic urethanes.

In further detail, the implant 100 may be generally cylindrical inshape, although this is not required, substantially flexible, and sizedappropriately for a convenient accommodation within the digestive tract.It is contemplated that various shapes, sizes and designs of the implantmay be constructed depending on the size and geometry of the cavitieswhere the implant 100 has to be placed. In various examples, the implant100 may have a length between 3-102 inches, 3-6 inches, 0.5-116 feet(0.15-6.1 meters), between 3-5 feet (0.9-1.5 meters), or about 2-4 feet(0.6-1.2 meters). However, the implant 100 may have a length of lessthan 0.5 feet (0.15 meters) or greater than 116 feet (6.1 meters) insome instances.

Once implanted in a patient, the stent 116 may exert a radially outwardforce to help secure the implant 100 to the body lumen. The implant 100may be positioned in the antrum-pyloric-duodenum, esophagus, thegastro-esophageal junction (GEJ) region (e.g., at or near the cardiawith the sleeve extending into the esophagus), or at or near the pyloruswith the sleeve extending through the stomach or other portions of thegastro-intestinal system. In one example, the implant 100 may bepositioned such that the stent 116 is positioned at the stomach outletwith the sleeve 124 bridging the pylorus. The flared structure of thestent 116 may use the stomach to anchor the implant 100 and act as ananti-migration mechanism for the implant 10. For example, the largeouter diameter of the proximal end 108 of the stent 116 may engage thestomach outlet to prevent or limit movement of the implant 100.

The implant 100 may further include a retrieval suture 126. The suture126 may include a retrieval suture loop 128 which may be configured tobe grasped by forceps or other tool during a clinical procedure forstent removal and or repositioning. In some cases, the retrieval sutureloop 128 may be formed by tying a knot 130 between, or otherwisecoupling (e.g., heat bonding, adhesive, etc.) a first end 132 and asecond end 134 of the retrieval suture. In other embodiments, theretrieval suture loop 128 may be formed at either the first end 132 orthe second end 134 of the retrieval suture 126. In such an instance, theend 132, 134 free from the retrieval suture loop 128 may be coupled tothe stent 100 or the opposing end 132, 134 of the retrieval suture 126,although this is not required.

The suture 126 may be interwoven with the stent frame 118 at intervalsalong a length of the implant 100 to create a plurality of suture loops136 a, 136 b, 136 c (collectively, 136). While the illustrative implant100 is shown and described has having three suture loops 136, it iscontemplated that the implant 100 may include fewer than or more thanthree suture loops 136, as desired. For example, the implant 100 mayinclude two, three, four, five, or more suture loops 136. It iscontemplated that the suture loops 136 may be positioned at regular oreven intervals throughout the overall length of the implant 100.However, in other embodiments, the suture loops 136 may be positioned ateccentric or uneven intervals along the length of the implant 100, asdesired. In some embodiments, one, two or more, or all of the sutureloops 136 may extend entirely around the circumference (e.g., 360°) ofthe stent frame 118. In other embodiments, one, two or more, or all ofthe suture loops 136 may extend less than 360° about the circumferenceof the stent frame 118. In some embodiments, one or more of the sutureloops 136 may extend 350° or less, 300° or less, 270° or less, 225° orless, 180° or less, 135° or less, etc. In yet other embodiments, one,two or more, or all of the suture loops may extend more than 360° aboutthe circumference of the stent frame 118.

The suture loops 136 may be formed from a single unitary suture 126. Itis contemplated that the suture 126 may be interwoven with the stentframe 118 such that the suture loops 136 may be constrained in apredetermined sequential order. In some cases, the proximal loop 136 aand/or the intermediate loop 136 b may not extend in a continuous loop.Rather, the proximal loop 136 a and/or the intermediate loop 136 b maybe broken into sections by longitudinally extending interconnectinglinks or segments 146, 170 which extend between the proximal loop 136 aand the intermediate loop 136 b and by longitudinally extendinginterconnecting links or segments 154, 162 which extend between theintermediate loop 136 b and the distal loop 136 b.

The suture 126 may be interwoven with the stent frame 118 by threadingone of the ends 132, 134 around the proximal end 108 of the implant 100beginning at a first circumferential location 138 and moving (e.g.,threading) in a first direction. In the illustrative example, the suture126 is described as initially being threaded in a clockwise direction.However, the reverse configuration in which the suture is initiallythreaded in a counterclockwise direction is also contemplated. Thesuture 126 may be threaded around about one half of the circumference ofthe implant 100 such that a first segment 140 of the suture 126 extendsbetween the first circumferential location 138 and a secondcircumferential location 142. The first and second circumferentiallocations 138, 142 may be positioned at a similar longitudinal distance(e.g., in a direction extending generally parallel to the longitudinalaxis 144 of the implant 100) from the first end 108 of the implant 100.In some cases, the suture 126 may be threaded such that it is interwovenwith the stent frame 118 such that a portion of the suture 126 is withinthe lumen 106 of the implant 100 and a portion of the suture 126 ispositioned along an exterior surface of the implant 100 (e.g., such thatit will be in contact with a vessel lumen when the implant 100 isdeployed within the body).

At the second circumferential location 142, the suture 126 may bethreaded along a length of implant 100 in a direction towards the distalend 110 such that a second longitudinally extending interconnectingsegment 146 of the suture 126 extends along a length of the implant 100in a generally linear direction. The length of the second segment 146 ofthe suture 126 may vary depending on the application. For example, someimplants 100 may include radially extending quills (not explicitlyshown) configured to engage a body tissue. The second segment 146 may beconfigured to extend along a length equal to or greater to a length ofthe implant 100 including the radially extending quills. This is justone example. Other features of the implant 100, such as, but not limitedto, the length of the implant 100 and/or the length of the stent 116portion may be used to determine the length of the second segment 146 ofthe suture 126.

The second segment 146 of the suture 126 may extend from the secondcircumferential location 142 to a third circumferential location 148.The second circumferential location 142 and the third circumferentiallocation 148 may be at similar radial points about the circumference ofthe implant 100 but spaced a distance along the length thereof. At thethird circumferential location 148, a third segment 150 of the suture126 may be threaded in a radial direction about the circumference of theimplant 100 in a second direction (e.g., counterclockwise), opposite tothe first direction. The suture 126 may be threaded around about onehalf of the circumference of the implant 100 such that the third segment150 of the suture 126 extends between the third circumferential location148 and a fourth circumferential location 152 to form a segment of theintermediate suture loop 136 b. In some embodiments, the thirdcircumferential location 148 and the fourth circumferential location 152may be may be positioned at a similar longitudinal distance (e.g., in adirection extending generally parallel to the longitudinal axis 144 ofthe implant 100) from the first end 108 of the implant 100.

At the fourth circumferential location 152, the suture 126 may bethreaded along a length of implant 100 in a direction towards the distalend 114 of the sleeve 124 such that a fourth longitudinally extendinginterconnecting segment 154 of the suture 126 extends along a length ofthe implant 100 in a generally linear direction. The length of thefourth segment 154 of the suture 126 may vary depending on theapplication. In some cases, the fourth segment 154 may extend to thedistal end 114 of the sleeve 124, although this is not required. Inother embodiments, the fourth segment 154 may extend to a point proximalto the distal end 114 of the sleeve 124. The fourth segment 152 of thesuture 126 may extend between the fourth circumferential location 152and a fifth circumferential location 156. The fourth circumferentiallocation 152 and the fifth circumferential location 156 may be atsimilar radial points about the circumference of the implant 100 butspaced a distance along the length thereof.

At the fifth circumferential location 156, a fifth segment 158 of thesuture 126 may be threaded in a radial direction about the circumferenceof the implant 10 in the first direction (e.g., the same direction asthe first segment 140). The fifth segment 158 may extend between thefifth circumferential location 156 and a sixth circumferential location160 to form the distal suture loop 136 c. In some embodiments, the fifthcircumferential location 156 and the sixth circumferential location 160may be at substantially the same radial point about the circumference ofthe implant 100 such that the distal suture loop 136 c extendssubstantially or entirely 360° about the circumference of the implant100. In other embodiments the fifth circumferential location 156 and thesixth circumferential location 160 may be radially spaced from oneanother by, for example, 1° or less, 5° or less, 10° or less, 20° orless, etc.

At the sixth circumferential location 160, the suture 126 may bethreaded along a length of implant 100 in a direction towards the firstend 108 such that a sixth longitudinally extending interconnectingsegment 162 of the suture 126 extends along a length of the implant 100in a linear direction generally parallel to the longitudinal axis 144.The length of the sixth segment 162 of the suture 126 may be about thesame length as the fourth segment 154 of the suture 126. The sixthsegment 162 of the suture 126 may extend between the sixthcircumferential location 160 and a seventh circumferential location 164.In some cases, the fourth and/or sixth segments 154, 162 of the suture126 may not be interwoven with the stent body 118 and/or flexible sleeve124 but rather extend along an inner or outer surface of the stent body118 and/or flexible sleeve 124.

At the seventh circumferential location 164, a seventh segment 166 ofthe suture 126 may be threaded in a radial direction about thecircumference of the implant 100 in the second direction (e.g.,counterclockwise), opposite to the first direction. The suture 126 maybe threaded around about one half of the circumference of the implant100 such that the seventh segment 166 of the suture 126 extends betweenthe seventh circumferential location 164 and an eighth circumferentiallocation 168 to form another portion of the intermediate suture loop 136b. Together, the third segment 150 and the seventh segment 166 of thesuture 126 may form the intermediate suture loop 136 b. In someembodiments, the seventh circumferential location 164 and the eighthcircumferential location 168 may be positioned at a similar longitudinaldistance (e.g., in a direction extending generally parallel to thelongitudinal axis 144 of the implant 100) from the first end 108 of theimplant 100. It is further contemplated that the seventh and eighthcircumferential locations 164, 168 may be positioned at a similarlongitudinal distance from the first end 108 of the implant 100 as thethird and fourth circumferential locations 148, 152. In someembodiments, the seventh circumferential location 164 and the eighthcircumferential location 168 may be at substantially the same radialpoint about the circumference of the implant 100 such that theintermediate suture loop 136 b extends substantially or entirely 360°about the circumference of the implant 100. In other embodiments theseventh circumferential location 164 and the eighth circumferentiallocation 168 may be radially spaced from one another by, for example, 1°or less, 5° or less, 10° or less, 20° or less, etc.

At the eighth circumferential location 168, the suture 126 may bethreaded along a length of implant 100 in a direction towards the firstend 108 such that an eighth longitudinally extending interconnectingsegment 170 of the suture 126 extends along a length of the implant 100in a linear direction generally parallel to the longitudinal axis 144.The length of the eighth segment 170 of the suture 126 may be about thesame length as the second segment 146 of the suture 126. The eighthsegment 170 of the suture 126 may extend between the eighthcircumferential location 168 and a ninth circumferential location 172.In some cases, the second and/or eighth segments 146, 170 of the suture126 may not be interwoven with the stent body 118 and/or flexible sleeve124 but rather extend along an inner or outer surface of the stent body118 and/or flexible sleeve 124.

At the ninth circumferential location 172, a ninth segment 174 of thesuture 126 may be threaded in a radial direction about the circumferenceof the implant 100 in the first direction (e.g., clockwise). The suture126 may be threaded around about one half of the circumference of theimplant 100 such that the ninth segment 172 of the suture 126 extendsbetween the ninth circumferential location 172 and a tenthcircumferential location 176 to form another portion of the proximalsuture loop 136 a. Together, the first segment 140 and the ninth segment174 of the suture 126 may form the proximal suture loop 136 a. In someembodiments, the ninth circumferential location 172 and the tenthcircumferential location 176 may be positioned at a similar longitudinaldistance (e.g., in a direction extending generally parallel to thelongitudinal axis 144 of the implant 100) from the first end 108 of theimplant 100. It is further contemplated that the ninth and tenthcircumferential locations 172, 176 may be positioned at a similarlongitudinal distance from the first end 108 of the implant 100 as thefirst and second circumferential locations 138, 142. In someembodiments, the ninth circumferential location 172 and the tenthcircumferential location 176 may be at substantially the same radialpoint about the circumference of the implant 100 such that the proximalsuture loop 136 a extends substantially or entirely 360° about thecircumference of the implant 100. In other embodiments the ninthcircumferential location 172 and the tenth circumferential location 176may be radially spaced from one another by, for example, 1° or less, 5°or less, 10° or less, 20° or less, etc. A first end 132 of the suture126 may extend from the first circumferential location 138 and thesecond end 134 of the suture 126 may extend from the tenthcircumferential location 176. The ends 132, 134 of the suture 126 may betied to form a knot 130, glued, and the knot 130 subsequently cured.

It is contemplated that in embodiments where it is desired for thesuture 126 to include suture loops 136 which extend around less than theentire circumference, the suture 126 may be initially threaded abouthalf of the length of the desired final arc. For example, as will bedescribed in more detail herein, if the finished suture loop 136 is toextend about 180° about the circumference of the implant 100, the suture126 may be initially threaded about 90° around the circumference beforebeing threaded down a length of the implant 100.

To collapse the implant 100, the retrieval suture loop 128, or the firstsuture loop 136 a in the absence of the retrieval suture loop 128, maybe pulled or otherwise actuated in a proximal direction. It iscontemplated that the direction of actuation (e.g., proximal or distal)required to actuate the suture 126 may be dependent on the direction inwhich the suture 126 is interwoven with the stent frame 118. As theretrieval suture loop 128, or the first suture loop 136 a in the absenceof the retrieval suture loop 128, is actuated, the suture loops 136begin to constrain or reduce the diameter of the implant 100, as shownin FIG. 5, which illustrates a side view of the illustrative implant 100during suture 126 actuation. The distal suture loop 136 c may beconstrained first, causing the distal end 114 of the sleeve 124 tocollapse or reduce in diameter before the first end 108. Continuedactuation of the retrieval suture loop 128 may cause first end 108 ofthe implant 100 to also be reduced in diameter, as shown in FIG. 6. Itis contemplated that the intermediate suture loop 136 b may not beactuated until the slack is removed from the preceding longitudinallyextending suture loop 136 c and the suture connection links 154, 162 aredrawn taut to apply a force to the next suture loop 136 b. Similarly, itis contemplated that the proximal suture loop 136 a may not be actuateduntil the slack is removed from the preceding longitudinally extendingsuture loop 136 b and the suture connection links 146, 170 are drawntaut to apply a force to the next suture loop 136 a. Such aconfiguration may allow the sleeve 124 to be retracted into the stent116 for removal. However, this is not required. In some instances, theconnection links 154, 162 and the connection links 146, 170 may have alength such that the suture loops 136 simultaneously (or approximatelysimultaneously) constrain the implant 100 along its length.

FIG. 7A illustrates a side view of another illustrative endoluminalimplant or stent 200. FIG. 7B is a top end view of the illustrativeendoluminal implant 200 of FIG. 7A. In some instances, the stent 200 maybe formed from an elongated tubular stent frame 202. While the stent 200is described as generally tubular, it is contemplated that the stent 200may take any cross-sectional shape desired. The stent 200 may have afirst, or proximal end 204, a second, or distal end 206, and anintermediate region 208 disposed between the first end 204 and thesecond end 206. The stent 200 may include a lumen 210 extending from afirst opening adjacent the first end 204 to a second opening adjacent tothe second end 206 to allow for the passage of food, fluids, etc.

The stent 200 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 200 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 200 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 202 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 202 may be braidedwith one filament. In other embodiments, the stent frame 202 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 202 maybe knitted, such as the ULTRAFLEX™ stents made by Boston ScientificCorp. In yet another embodiment, the stent frame 202 may be of a knottedtype, such the PRECISION COLONIC™ stents made by Boston Scientific Corp.In still another embodiment, the stent frame 202 may be laser cut, suchas the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 200 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 200to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 200 tobe removed with relative ease as well. For example, the stent 200 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 200 maybe self-expanding (i.e., configured to automatically radially expandwhen unconstrained). In some embodiments, fibers may be used to make thestent 200, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 200 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 200 maybe self-expanding while in other embodiments, the stent 200 may beexpand by an expansion device (such as, but not limited to a ballooninserted within the lumen 210 of the stent 200). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 200 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 210 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 200may include a first end region 212 proximate the proximal end 204 and asecond end region 214 proximate the second end 206. In some embodiments,the first end region 212 and the second end region 214 may includeretention features or anti-migration flared regions (not explicitlyshown) having enlarged diameters relative to the intermediate portion208. The anti-migration flared regions, which may be positioned adjacentto the first end 204 and the second end 206 of the stent 200, may beconfigured to engage an interior portion of the walls of the esophagus,stomach or other body lumen. In some embodiments, the retentionfeatures, or flared regions may have a larger diameter than thecylindrical intermediate region 208 of the stent 200 to prevent thestent 200 from migrating once placed in the esophagus, stomach, or otherbody lumen. It is contemplated that a transition from thecross-sectional area of the intermediate region 208 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 200 mayhave a uniform diameter from the proximal end 204 to the distal end 206,as shown in FIG. 7A.

It is contemplated that the stent 200 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 200to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 200 tobe removed with relative ease as well. For example, the stent 200 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 200 maybe self-expanding or require an external force to expand the stent 200.In some embodiments, composite filaments may be used to make the stent200, which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 200 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 200, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 200, or portions thereof, may be biostable.

The implant 200 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 200, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 200 may further include a retrieval suture 216. The suture216 may include a retrieval suture loop 218 which may be configured tobe grasped by forceps or other tool during a clinical procedure forstent removal and or repositioning. In some cases, the retrieval sutureloop 218 may be formed by tying a knot 220 between, or otherwisecoupling (e.g., heat bonding, adhesive, etc.) a first end 222 and asecond end 224 of the retrieval suture. In other embodiments, theretrieval suture loop 218 may be formed at either the first end 222 orthe second end 224 of the retrieval suture 216. In such an instance, theend 222, 224 free from the retrieval suture loop 218 may be coupled tothe stent 200 or the opposing end 222, 224 of the retrieval suture 216,although this is not required.

The suture 216 may be interwoven with the stent frame 202 at intervalsalong a length of the implant 200 to create a plurality of suture loops226 a, 226 b (collectively, 226). While the illustrative implant 200 isshown and described has having two suture loops 226, it is contemplatedthat the implant 200 may include more than two suture loops 226, asdesired. For example, the implant 200 may include three, four, five, ormore suture loops 226. It is contemplated that the suture loops 226 maybe positioned at regular or even intervals throughout the overall lengthof the implant 200. However, in other embodiments, the suture loops 226may be positioned at eccentric or uneven intervals along the length ofthe implant 200, as desired. In some embodiments, one, two or more, orall of the suture loops 226 may extend less than an entire circumferenceor less than 360° of the circumference of the stent frame 202. In theillustrative embodiment, the suture loops 226 may extend about or havean arc length of 180° or about half of the circumference of the stentframe 202. In other embodiments, one, two or more, or all of the sutureloops 226 may extend or have an arc length of less than 360° about thecircumference of the stent frame 202. In some embodiments, one or moreof the suture loops 226 may extend 350° or less, 300° or less, 270° orless, 225° or less, 180° or less, or 135° or less around thecircumference of the stent frame 202. In yet other embodiments, one, twoor more, or all of the suture loops may extend about 360° or more than360° about the circumference of the stent frame 202, as desired. It isfurther contemplated that all of the suture loops 226 need not have thesame arc length. For example, a first suture loop may extend about 180°while a second suture loop may extend about 270°. This is just oneexample. It is contemplated that the size and shape of each of thesuture loops 226 may be selected to customize constrainment of the stent200. For example, if barbs or protrusions 260 are provided on one sideof the stent 200, it may be desirable to constrain the side of the stent200 having the barbs or protrusions 260 in order to disengage the barbsor protrusions 260 from a luminal wall of a body lumen prior to removingor repositioning the stent 200. In some instances, the barbs orprotrusions 260 may be positioned only around a portion of thecircumference of the stent 200, leaving a remainder of the circumferenceof the stent 200 devoid of any barbs or protrusions. For example, thebarbs or protrusions 260 may be positioned only around 270° or less,225° or less, 180° or less, or 135° or less of the circumference of thestent 200. Accordingly, the suture loops 226 may extend around theportion of the circumference of the stent 200 including the barbs orprotrusions 260, while not extending around the remainder of thecircumference of the stent 200, which is devoid of barbs or protrusions.

In the illustrative embodiment, the stent 200 may have a firstcircumferential region 211 of the circumference of the stent 200 whichis directly manipulated by the suture 216 and a second circumferentialregion 213 of the circumference of the stent 200 which is not directlymanipulated by the suture 216. The first circumferential region 211 ofthe circumference of the stent 200 may correspond to the portion of thecircumference of the stent 200 having the barbs or protrusions 260,while the second circumferential region 213 of the circumference of thestent 200 may correspond to the portion of the circumference of thestent 200 devoid of any barbs or protrusions. When the stent 200 is inthe unconstrained configuration (e.g., as shown in FIGS. 7A and 7B), thefirst circumferential region 211 may have a first arc length and thesecond circumferential region 213 may have a second arc length. When thesuture loops 226 extend about 180° about the circumference, the arclengths of the first and second circumferential regions 211, 213 may beapproximately equal, although this is not required. It should beunderstood that the arc length of the first and second circumferentialregions 211, 213 correspond to the circumferential distance the sutureloops 226 extend about the circumference of the stent 200.

The suture loops 226 may be formed from a single unitary suture 216. Itis contemplated that the suture 216 may be interwoven with the stentframe 202 such that the suture loops 226 may be constrained in apredetermined sequential order. In some cases, the proximal loop 226 amay not extend in a continuous loop. Rather, the proximal loop 226 a maybe broken into sections by longitudinally extending interconnectingsegments 46, 58 which extend between the proximal loop 226 a and thedistal loop 226 b.

The suture 216 may be interwoven with the stent frame 202 by threadingone of the ends 222, 224 around the proximal end 204 of the implant 200beginning at a first circumferential location 230 and moving (e.g.,threading) in a first direction. In the illustrative example, the suture216 is described as initially being threaded in a clockwise direction.However, the reverse configuration in which the suture is initiallythreaded in a counterclockwise direction is also contemplated. Thesuture 216 may be threaded around about one quarter of the circumference(or about 90°) of the implant 200 such that a first segment 232 of thesuture 216 extends between the first circumferential location 230 and asecond circumferential location 234. The first and secondcircumferential locations 230, 234 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 228 of the implant 200) from the first end 204of the implant 200. In some cases, the suture 216 may be threaded suchthat it is interwoven with the stent frame 202 such that a portion ofthe suture 216 is within the lumen 210 of the implant 200 and a portionof the suture 216 is positioned along an exterior surface of the implant200 (e.g., such that it will be in contact with a vessel lumen when theimplant 200 is deployed within the body). At the second circumferentiallocation 234, the suture 216 may be threaded along a length of implant200 in a direction towards the second end 206 such that a secondlongitudinally extending interconnecting segment 236 of the suture 216extends along a length of the implant 200 in a generally lineardirection. The length of the second segment 236 of the suture 216 mayvary depending on the application. For example, some implants 200 mayinclude radially extending barbs or protrusions 260 configured to engagea body tissue. The second segment 236 may be configured to extend alonga length equal to or greater to a length of the implant 200 includingthe radially extending barbs or protrusions 260. This is just oneexample. Other features of the implant 200, such as, but not limited to,the length of the implant 200 may be used to determine the length of thesecond segment 236 of the suture 216.

The second segment 236 of the suture 216 may extend from the secondcircumferential location 234 to a third circumferential location 238.The second circumferential location and the third circumferentiallocation 238 may be at similar radial points about the circumference ofthe implant 200 but spaced a distance along the length thereof. At thethird circumferential location 238, a third segment 240 of the suture216 may be threaded radially about the circumference of the implant 200in a second direction (e.g., counterclockwise), opposite to the firstdirection. The third segment 240 may extend between the thirdcircumferential location 238 and a fourth circumferential location 242to form a suture loop 226 b. The arc length of the third segment 240 maybe less than 360° of the circumference. In some cases, the arc length ofthe third segment 240 may be in the range of 350° or less, 300° or less,270° or less, 225° or less, 180° or less, 135° or less, etc. of thecircumference. The third circumferential location 238 and the fourthcircumferential location 242 may be radially spaced from one another by,for example, 10° or more, 60° or more, 90° or more, 135° or more, 180°or more, 225° or more, etc.

At the fourth circumferential location 242, the suture 216 may bethreaded along a length of implant 200 in a direction towards the firstend 204 such that a fourth longitudinally extending interconnectingsegment 244 of the suture 216 extends along a length of the implant 200in a direction to the longitudinal axis 228. The length of the fourthsegment 244 of the suture 216 may be about the same length as the secondsegment 236 of the suture 216. The fourth segment 244 of the suture 216may extend between the fourth circumferential location 242 and a fifthcircumferential location 246. In some cases, the second and/or fourthsegments 236, 244 of the suture 216 may not be interwoven with the stentbody 202 but rather extend along an inner or outer surface of the stentbody 202. In some embodiments, the first, second, and fifthcircumferential locations 230, 234, 246 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 228 of the implant 200) from the first end 204of the implant 200.

From the fifth circumferential location 246, the suture 216 may bethreaded through the stent body 202 in the first direction (e.g., awayfrom the first segment 232) to form a fifth segment 248 of the suture216. The fifth segment 248 of the suture 216 may be threaded through thestent body 202 to a sixth circumferential location 250 and/or until itmeets the first circumferential location 230 (e.g., the starting point)to form the proximal loop 226 a. As described above, the proximal sutureloop 226 a may be formed of discontinuous or broken segments 232, 248.In some embodiments, the fifth segment 248 ceases to be interwoven withthe stent body 202 before the suture 216 reaches the firstcircumferential location 230. For example, the first circumferentiallocation 230 may be radially spaced from the sixth circumferentiallocation 250 may be radially spaced from one another by, for example, 1°or less, 5° or less, 10° or less, 20° or less, etc. A first end 222 ofthe suture 216 may extend from the first circumferential location 230and the second end 224 of the suture 216 may extend from the sixthcircumferential location 250. The ends 222, 224 of the suture 216 may betied to form a knot 220, glued, and the knot 220 subsequently cured.

It is contemplated that in embodiments where it is desired for thesuture 216 to include suture loops 226 which extend around less than theentire circumference, as shown, the suture 216 may be initially threadedabout half the length of the desired final arc length. For example, ifthe finished suture loop 226 is to extend about 180° about thecircumference of the implant 200, the suture 216 may be initiallythreaded about 90° around the circumference before being threaded down alength of the implant 200, as shown and described.

To collapse the implant 200, the retrieval suture loop 218, or the firstsuture loop 226 a in the absence of the retrieval suture loop 218, maybe pulled or otherwise actuated in a proximal direction. It iscontemplated that the direction of actuation (e.g., proximal or distal)required to actuate the suture 216 may be dependent on the direction inwhich the suture 216 is interwoven with the stent frame 202. As theretrieval suture loop 218, or the first suture loop 226 a in the absenceof the retrieval suture loop 218, is actuated, the suture loops 226begin to constrain or reduce the diameter of the implant 200, as shownin FIG. 8A, which illustrates a side view of the illustrative implant200 during suture 216 actuation. As the suture loops 226 are positionedto one side (e.g., circumferential region 211) of the implant 200, theimplant 200 may constrain or collapse more significantly or to a greaterextent adjacent to the suture loops 226. The distal or second sutureloop 226 b may be constrained first, causing the distal end portion 206of the stent body 202 to collapse or reduce in diameter before the firstend 204. Continued actuation of the retrieval suture loop 218 may causefirst end 204 of the implant 200 to also be reduced in diameter, asshown in FIG. 8A. It is contemplated that the proximal or first sutureloop 226 a may not be actuated until the slack is removed from thepreceding longitudinally extending suture loop 226 b and the sutureconnection links 236, 244 are drawn taut to apply a force to the nextsuture loop 226 a. However, this is not required. In some instances, theconnection links 236, 244 may have a length such that the suture loops226 simultaneously (or approximately simultaneously) constrain theimplant 200 along its length.

It is contemplated that the orientation of the suture loops 226 maypreferentially collapse the first circumferential region 211 of thestent 200 which includes the barbs or projections 260. This may causethe arc length of the first circumferential region 211 to shorten(relative to the unconstrained configuration) as the circumferentialregion 211 is collapsed, as shown in FIG. 8B, which illustrates a topview of the illustrative stent of FIG. 8A. Constrainment and shorteningof the arc length of the first circumferential region 211 may disengagethe barbs or projections 260 from the luminal wall of a body lumen tofacilitate removal of the stent 200 from the body lumen and/orfacilitate repositioning of the stent 200 in the body lumen. In somecases, constrainment of the first circumferential region 211 may causesome deformation and/or constrainment of the second circumferentialregion 213. In some cases, the second circumferential region 213 mayassume a more oblong shape as the first circumferential region 211 isconstrained, as shown in FIG. 8B. In some cases, the arc length of thesecond circumferential region 211 may remain approximately constant, mayslightly increase or may slightly decrease relative to the unconstrainedconfiguration.

FIG. 9 illustrates a side view of an illustrative endoluminal implant orstent 300. In some instances, the stent 300 may be formed from anelongated tubular stent frame 302. While the stent 300 is described asgenerally tubular, it is contemplated that the stent 300 may take anycross-sectional shape desired. The stent 300 may have a first, orproximal end 304, a second, or distal end 306, and an intermediateregion 308 disposed between the first end 304 and the second end 306.The stent 300 may include a lumen 310 extending from a first openingadjacent the first end 304 to a second opening adjacent to the secondend 306 to allow for the passage of food, fluids, etc.

The stent 300 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 300 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 300 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 302 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 302 may be braidedwith one filament. In other embodiments, the stent frame 302 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 302 maybe knitted, such as the ULTRAFLEX™ stents made by Boston ScientificCorp. In yet another embodiment, the stent frame 302 may be of a knottedtype, such the PRECISION COLONIC™ stents made by Boston Scientific Corp.In still another embodiment, the stent frame 302 may be laser cut, suchas the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 300 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys, and/or polymers, as desired, enabling the stent 300to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 300 tobe removed with relative ease as well. For example, the stent 300 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 300 maybe self-expanding (i.e., configured to automatically radially expandwhen unconstrained). In some embodiments, fibers may be used to make thestent 300, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 300 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 300 maybe self-expanding while in other embodiments, the stent 300 may beexpand by an expansion device (such as, but not limited to a ballooninserted within the lumen 310 of the stent 300). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 300 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 310 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 300may include a first end region 312 proximate the proximal end 304 and asecond end region 314 proximate the second end 306. In some embodiments,the first end region 312 and the second end region 314 may includeretention features or anti-migration flared regions (not explicitlyshown at the second end region 314) having enlarged diameters relativeto the intermediate portion 308. The anti-migration flared regions,which may be positioned adjacent to the first end 304 and the second end306 of the stent 300, may be configured to engage an interior portion ofthe walls of the esophagus, stomach or other body lumen. In someembodiments, the retention features, or flared regions may have a largerdiameter than the cylindrical intermediate region 308 of the stent 300to prevent the stent 300 from migrating once placed in the esophagus,stomach, or other body lumen. It is contemplated that a transition fromthe cross-sectional area of the intermediate region 308 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 300 mayhave a uniform diameter from the proximal end 304 to the distal end 306.

It is contemplated that the stent 300 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 300to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 300 tobe removed with relative ease as well. For example, the stent 300 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 300 maybe self-expanding or require an external force to expand the stent 300.In some embodiments, composite filaments may be used to make the stent300, which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 300 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 300, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 300, or portions thereof, may be biostable.

The implant 300 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 300, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 300 may further include a retrieval suture 316. Theretrieval suture 316 may be formed from a first suture strand 318 a anda second suture strand 318 b (collectively, 318). The suture strands 318a, 318 b may be a single strand which has been doubled back on itself,as shown at 319 in FIG. 9. It is contemplated that in such an instances,the retrieval suture 316 may be doubled back on itself prior tointerweaving the retrieval suture 316 with the implant 300. In otherembodiments, the suture strands 318 a, 318 b separate strands extendingside by side. While the retrieval suture 316 is described as having twosuture strands 318, it is contemplated that the retrieval sutures 316may include fewer than two strands or more than two strands, as desired.The region 319 where the suture 316 is doubled back on itself may definea first end 320 a, 320 b of the suture strands 318 while the free endsof retrieval suture 316 may form a second end 322 a, 322 b of eachstrand 318 a, 318 b. The first end 320 a, 320 b (collectively, 320) ofeach strand 318 a, 318 b may be knotted with the second end 322 a, 322 b(collectively, 322) of each strand 318 a, 318 b to form a knot 324. Insome cases, the knot 324 may be a slip knot or other knot which allowseither the first or second ends 320, 322 to be grasped and actuated byforceps or other tool during a clinical procedure for stent removal andor repositioning. It is contemplated that the use of a sliding knot 324may reduce or eliminate breakage of the retrieval suture 316 duringremoval or repositioning of the implant 300.

The retrieval suture 316 may be interwoven with the stent frame 302 atintervals along a length of the implant 300 to create a plurality ofsuture loops 326 a, 326 b (collectively, 326). While the illustrativeimplant 300 is shown and described has having two suture loops 326, itis contemplated that the implant 300 may include more than two sutureloops 326, as desired. For example, the implant 300 may include three,four, five, or more suture loops 326. It is contemplated that the sutureloops 326 may be positioned at regular or even intervals throughout theoverall length of the implant 300. However, in other embodiments, thesuture loops 326 may be positioned at eccentric or uneven intervalsalong the length of the implant 300, as desired. It is contemplated thatthe suture loops 326 may be positioned to facilitate retrieval,repositioning, and/or reshaping of the stent 300. For example, in astent 300 having two or more flared or enlarged regions, as in theAXIOS® stent made and distributed by Boston Scientific Corp., a firstretrieval suture loop 326 a may be positioned adjacent to the firstflare and a second retrieval suture loop 326 b may be positionedadjacent to the second flare.

In some embodiments, one, two or more, or all of the suture loops 326may extend entirely around the circumference (e.g., 360°) of the stentframe 302. In other embodiments, one, two or more, or all of the sutureloops 326 may extend less than 360° about the circumference of the stentframe 302. In some embodiments, one or more of the suture loops 326 mayextend 350° or less, 300° or less, 270° or less, 225° or less, 180° orless, 135° or less, etc. In yet other embodiments, one, two or more, orall of the suture loops may extend more than 360° about thecircumference of the stent frame 302.

As described above, the suture loops 326 may be formed from two or moresuture strands 318. It is contemplated that the suture strands 318 maybe interwoven with the stent frame 302 such that the suture loops 326may be constrained in a predetermined sequential order. In some cases,the proximal loop 326 a may not extend in a continuous loop. Rather, theproximal loop 326 a may be broken into sections by longitudinallyextending interconnecting segments 336, 344 which extend between theproximal loop 326 a and the distal loop 326 b.

The suture strands 318 may be interwoven with the stent frame 302 bythreading one of the ends 320, 322 around the proximal end 304 of theimplant 300 beginning at a first circumferential location 328 and moving(e.g., threading) in a first direction. In the illustrative example, thesuture 316 is described as initially being threaded in a clockwisedirection. However, the reverse configuration in which the suture isinitially threaded in a counterclockwise direction is also contemplated.The suture 316 may be threaded around about one half of thecircumference of the implant 300 such that a first segment 330 of thesuture 316 extends between the first circumferential location 328 and asecond circumferential location 332. The first and secondcircumferential locations 328, 332 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 334 of the implant 300) from the first end 304of the implant 300. In some cases, the suture 316 may be threaded suchthat it is interwoven with the stent frame 302 such that a portion ofthe suture 316 is within the lumen 310 of the implant 300 and a portionof the suture 316 is positioned along an exterior surface of the implant300 (e.g., such that it will be in contact with a vessel lumen when theimplant 300 is deployed within the body). At the second circumferentiallocation 332, the suture 316 may be threaded along a length of implant300 in a direction towards the second end 306 such that a secondlongitudinally extending interconnecting segment 336 of the suture 316extends along a length of the implant 300 in a generally lineardirection. The length of the second segment 336 of the suture 316 mayvary depending on the application. For example, some implants 300 mayinclude radially extending quills (not explicitly shown) configured toengage a body tissue. The second segment 336 may be configured to extendalong a length equal to or greater to a length of the implant 300including the radially extending quills. This is just one example. Otherfeatures of the implant 300, such as, but not limited to, the length ofthe implant 300 may be used to determine the length of the secondsegment 336 of the suture 316.

The second segment 336 of the suture 316 may extend from the secondcircumferential location 332 to a third circumferential location 338.The second circumferential location 332 and the third circumferentiallocation 338 may be at similar radial points about the circumference ofthe implant 300 but spaced a distance along the length thereof. At thethird circumferential location 338, a third segment 340 of the suture316 may be threaded radially about the circumference of the implant 300in a second direction (e.g., counterclockwise), opposite to the firstdirection. The third segment 340 may extend between the thirdcircumferential location 338 and a fourth circumferential location 342to form a suture loop 326 b. In some embodiments, the thirdcircumferential location 338 and the fourth circumferential location 342may be at substantially the same radial point about the circumference ofthe implant 300 such that the suture loop 326 b extends substantially orentirely 360° about the circumference of the implant 300. In otherembodiments the third circumferential location 338 and the fourthcircumferential location 342 may be radially spaced from one another by,for example, 1° or less, 5° or less, 10° or less, 20° or less, etc.

At the fourth circumferential location 342, the suture 316 may bethreaded along a length of implant 300 in a direction towards the firstend 304 such that a fourth longitudinally extending interconnectingsegment 344 of the suture 316 extends along a length of the implant 300in a direction to the longitudinal axis 334. The length of the fourthsegment 344 of the suture 316 may be about the same length as the secondsegment 336 of the suture 316. The fourth segment 344 of the suture 316may extend between the fourth circumferential location 342 and a fifthcircumferential location 346. In some cases, the second and/or fourthsegments 336, 344 of the suture may not be interwoven with the stentbody 302 but rather extend along an inner or outer surface of the stentbody 302. In some embodiments, the first, second, and fifthcircumferential locations 328, 332, 346 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 334 of the implant 300) from the first end 304of the implant 300.

From the fifth circumferential location 346, the suture 316 may bethreaded through the stent body 302 in the first direction (e.g., awayfrom the first segment 330) to form fifth segment 348 of the suture 316.The fifth segment 348 of the suture 316 may be threaded through thestent body 302 to a sixth circumferential location 350 and/or until itmeets the first circumferential location 328 (e.g., the starting point)to form the proximal loop 326 a. As described above, the proximal sutureloop 326 a may be formed of discontinuous or broken segments 330, 348.In some embodiments, the fifth segment 348 ceases to be interwoven withthe stent body 302 before the suture 316 reaches the firstcircumferential location 328. For example, the first circumferentiallocation 328 may be radially spaced from the sixth circumferentiallocation 350 by, for example, 1° or less, 5° or less, 10° or less, 20°or less, etc. In the illustrated example, the second ends 322 of thesuture strands 318 may extend from the first circumferential location328 and the first ends 320 of the suture strands 318 may extend from thesixth circumferential location 350. The ends 320, 322 of the suture 316may be tied to form a slip knot 324, as described above.

To collapse the implant 300, an end 320, 322 of one of the suturestrands 318, may be pulled or otherwise actuated in a proximaldirection. It is contemplated that the direction of actuation (e.g.,proximal or distal) required to actuate the suture 316 may be dependenton the direction in which the suture 316 is interwoven with the stentframe 302. As the first ends 320 or second ends 322 are actuated, thesuture loops 326 begin to constrain or reduce the diameter (notexplicitly shown) of the implant 300. The distal or second suture loop326 b may be constrained first, causing the intermediate portion 308 ofthe stent body 302 to collapse or reduce in diameter before the firstend 304. Continued actuation of the sutures strands 318 may cause thefirst end 304 of the implant 300 to also be reduced in diameter (notexplicitly shown). It is contemplated that the proximal or first sutureloop 326 a may not be actuated until the slack is removed from thepreceding longitudinally extending suture loop 326 b and the sutureconnection links 336, 344 are drawn taut to apply a force to the nextsuture loop 326 a. However, this is not required. In some instances, theconnection links 336, 344 may have a length such that the suture loops326 simultaneously (or approximately simultaneously) constrain theimplant 300 along its length.

FIG. 10 illustrates a side view of an illustrative endoluminal implantor stent 400. In some instances, the stent 400 may be formed from anelongated tubular stent frame 402. While the stent 400 is described asgenerally tubular, it is contemplated that the stent 400 may take anycross-sectional shape desired. The stent 400 may have a first, orproximal end 404, a second, or distal end 406, and an intermediateregion 408 disposed between the first end 404 and the second end 406.The stent 400 may include a lumen 410 extending from a first openingadjacent the first end 404 to a second opening adjacent to the secondend 406 to allow for the passage of food, fluids, etc.

The stent 400 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 400 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 400 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 402 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 402 may be braidedwith one filament. In other embodiments, the stent frame 402 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 402 maybe knitted, such as the ULTRAFLEX™ stents made by Boston ScientificCorp. In yet another embodiment, the stent frame 402 may be of a knottedtype, such the PRECISION COLONIC™ stents made by Boston Scientific Corp.In still another embodiment, the stent frame 402 may be laser cut, suchas the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 400 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys, and/or polymers, as desired, enabling the stent 400to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 400 tobe removed with relative ease as well. For example, the stent 400 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 400 maybe self-expanding (i.e., configured to automatically radially expandwhen unconstrained). In some embodiments, fibers may be used to make thestent 400, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 400 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 400 maybe self-expanding while in other embodiments, the stent 400 may beexpand by an expansion device (such as, but not limited to a ballooninserted within the lumen 410 of the stent 400). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 400 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 410 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 400may include a first end region 412 proximate the proximal end 404 and asecond end region 414 proximate the second end 406. In some embodiments,the first end region 412 and the second end region 414 may includeretention features or anti-migration flared regions (not explicitlyshown at the second end region 414) having enlarged diameters relativeto the intermediate portion 408. The anti-migration flared regions,which may be positioned adjacent to the first end 404 and the second end406 of the stent 400, may be configured to engage an interior portion ofthe walls of the esophagus, stomach or other body lumen. In someembodiments, the retention features, or flared regions may have a largerdiameter than the cylindrical intermediate region 408 of the stent 400to prevent the stent 400 from migrating once placed in the esophagus,stomach, or other body lumen. It is contemplated that a transition fromthe cross-sectional area of the intermediate region 408 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 400 mayhave a uniform diameter from the proximal end 404 to the distal end 406.

It is contemplated that the stent 400 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 400to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 400 tobe removed with relative ease as well. For example, the stent 400 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 400 maybe self-expanding or require an external force to expand the stent 400.In some embodiments, composite filaments may be used to make the stent400, which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 400 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 400, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 400, or portions thereof, may be biostable.

The implant 400 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 400, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 400 may further include a suture 416. The suture 416 may beinterwoven with the stent frame 402 at intervals along a length of theimplant 400 to create a plurality of suture loops 418 a, 418 b, 418 c(collectively, 418). While the illustrative implant 400 is shown anddescribed has having three suture loops 418, it is contemplated that theimplant 400 may include fewer than three or more than three suture loops418, as desired. For example, the implant 400 may include two, four,five, or more suture loops 418. It is contemplated that the suture loops418 may be positioned at regular or even intervals throughout theoverall length of the implant 400. However, in other embodiments, thesuture loops 418 may be positioned at eccentric or uneven intervalsalong the length of the implant 400, as desired. It is contemplated thatthe suture loops 418 may be positioned to facilitate retrieval,repositioning, and/or reshaping of the stent 400. For example, in astent 400 having two or more flared or enlarged regions, as in theAXIOS® stent made and distributed by Boston Scientific Corp., a firstsuture loop 418 a may be positioned adjacent to the first flare and asecond suture loop 418 b may be positioned adjacent to the second flare.

In some embodiments, the implant 400 may include a first plurality ofrings 424 a, 424 b, 424 c (collectively, 424) adjacent the proximal end404 of the implant, a second plurality of rings 426 a, 426 b, 426 c(collectively, 426) adjacent the intermediate region 408 of the implant400, and a third plurality of rings 428 a, 428 b, 428 c (collectively,428) adjacent the distal end 406 of the implant 400. The positioning ofthe rings 424, 426, 428 is not limited to the described and illustratedconfiguration. Rather, the positioning of the rings 424, 426, 428 may bedetermined by the desired location and quantity of the suture loops 418.For example, in some cases, a plurality of rings 424, 426, 428 may bepositioned at each location where a suture loop 418 is desired. However,this is not required. In some instances, a suture loop 418 may beprovided in the absence of a rings. Further, while each plurality ofrings 424, 426, 428 is illustrated as including three rings, it iscontemplate that each plurality of rings 424, 426, 428 may have fewerthan three rings or more than three rings, as desired. Further, eachplurality of rings 424, 426, 428 need not each have the same number ofrings.

Each ring 424 a, 424 b, 424 c of the first plurality of rings 424 may bepositioned at a similar longitudinal distance (e.g., in a directionextending generally parallel to the longitudinal axis 430 of the implant400). The rings 424 may be positioned about the circumference of thestent 400 at uniform intervals. For example, when three rings 424 areprovided, the rings 424 may be separated by approximately 120°. However,the rings 424 may be eccentric or uneven intervals, as desired. In somecases, the rings 424 may not be positioned about an entire circumferenceof the stent frame 402. For example, if the suture loops 418 extend lessan entire circumference or less than 360° about the stent 400, the rings424 may be positioned to coincide with the portion of the circumferencewith which the suture loops 418 extend.

Each ring 426 a, 426 b, 426 c of the second plurality of rings 426 maybe positioned at a similar longitudinal distance (e.g., in a directionextending generally parallel to the longitudinal axis 430 of the implant400). The rings 426 may be positioned about the circumference of thestent 400 at uniform intervals. For example, when three rings 426 areprovided, the rings 426 may be separated by approximately 120°. However,the rings 426 may be eccentric or uneven intervals, as desired. In somecases, the rings 426 may not be positioned about an entire circumferenceof the stent frame 402. For example, if the suture loops 418 extend lessan entire circumference or less than 360° about the stent 400, the rings426 may be positioned to coincide with the portion of the circumferencewith which the suture loops 418 extend.

Each ring 428 a, 428 b, 428 c of the third plurality of rings 428 may bepositioned at a similar longitudinal distance (e.g., in a directionextending generally parallel to the longitudinal axis 430 of the implant400). The rings 428 may be positioned about the circumference of thestent 400 at uniform intervals. For example, when three rings 428 areprovided, the rings 428 may be separated by approximately 120°. However,the rings 428 may be at eccentric or uneven intervals, as desired. Insome cases, the rings 428 may not be positioned about an entirecircumference of the stent frame 402. For example, if the suture loops418 extend less an entire circumference or less than 360° about thestent 400, the rings 428 may be positioned to coincide with the portionof the circumference with which the suture loops 418 extend.

In some embodiments, one, two or more, or all of the suture loops 418may extend entirely around the circumference (e.g., 360°) of the stentframe 402. In other embodiments, one, two or more, or all of the sutureloops 418 may extend less than 360° about the circumference of the stentframe 402. In some embodiments, one or more of the suture loops 418 mayextend 350° or less, 300° or less, 270° or less, 225° or less, 180° orless, 135° or less, etc. In yet other embodiments, one, two or more, orall of the suture loops may extend more than 360° about thecircumference of the stent frame 402.

As described above, the suture loops 418 may be formed from a retrievalsuture 416. It is contemplated that the suture 416 may be threaded orpassed through the openings of the rings 424, 426, 428 in place of or inaddition to interweaving the suture 418 with the stent frame 402. It iscontemplated that threading the suture 416 through the rings 424, 426,428 instead of the stent frame 402 or by using the rings to at leastpartially reduce the length of suture 416 that is interwoven with thestent frame 402 reduces the force required to actuate the suture 416 byreducing the frictional forces exerted on the suture 416.

It is contemplated that when the suture 416 is only passed through theopening of the rings 424, 426, 428, the rings 424, 426, 428 may befixedly attached to the stent frame 402. This may allow movement of therings 424, 426, 428 to be translated to the stent frame 402. In somecases, the first plurality of rings 424 and the third plurality of rings428 (e.g., the rings positioned adjacent to the proximal end 404 and thedistal end 406) may be fixedly coupled to the stent frame 402 while thesecond plurality of rings 426 may be movably coupled to the stent frame402. This is just one example. The rings 424, 426, 428 may be fixedly ormovably coupled in any configuration desired. Further, some rings ofeach plurality may be fixedly coupled while others of the same pluralityare movably coupled to the stent frame 402. It is contemplated that whenthe rings 424, 426, 428 are movably coupled to the stent frame 402, thesuture 416 may be at least partially interwoven with the stent frame 402near the movable rings 424, 426, 428 such that movement of the suture416 is translated to the stent frame 402.

The suture 416 may have a first end 420 coupled to a first ring 424 a inthe first plurality of rings 424 and a second end 422 coupled to a firstring 428 a in the third plurality of rings 428. The suture 416 beinterwoven with the rings 424, 426, 428 and/or stent frame 402 in anynumber of ways. In one example, the first end 420 of the suture 416 maybe coupled to the first ring 424 a in the first plurality of rings 424.The second end 422 of the suture 416 may be threaded through the openingin the second ring 424 b and then through the opening in the third ring424 c. The suture 416 may then be passed through the opening in thefirst ring 424 a to form the first suture loop 418 a. While the suture416 is described as being threaded in a clockwise direction, the reverseconfiguration is also contemplated. As described above, the firstplurality of rings 424 may be fixedly coupled to the stent frame 402such that the suture 416 is not required to be interwoven with the stentframe 402 in order to manipulate the stent frame 402 adjacent to thefirst plurality of rings 424.

Once the suture 416 has passed through the opening in the first ring 424a, the suture 416 may be directed towards a first ring 426 a in thesecond plurality of rings 426. In some cases, the second plurality ofrings 426 may be circumferentially offset from the first plurality ofrings 424. In such an instance, the longitudinally extending segment 432of the suture 416 which extends between the first plurality of rings 424and the second plurality of rings 426 may extend at a non-orthogonalangle to the plane formed by the second plurality of rings 426. In somecases, the longitudinally extending segment 432 may include rings inplace of or in addition to the rings 424, 426, 428 at the suture loops418.

The second end 422 of the suture 416 may be passed through the openingin the first ring 426 a. The suture 416 may then be directed towards andthrough the opening in the third ring 426 c (e.g., in a directionopposite the first suture loop 418 a, although this is not required).The suture 416 may then be directed from the third ring 426 c towardsand through the second ring 426 b. The suture 416 may then be passedthrough the opening in the first ring 426 a to form the second sutureloop 418 b. When the second plurality of rings 426 is not fixedlycoupled to the stent frame 402, the suture 416 may be at least partiallyinterwoven with the stent frame between the first ring 426 a and thethird ring 426 c, between the third ring 426 c and the second ring 426b, and/or between the second ring 426 b and the first ring 426 a.

Once the suture 416 has passed through the opening in the first ring 426a to complete the suture loop 418 b, the suture 416 may be directedtowards a first ring 428 a in the third plurality of rings 428. In somecases, the third plurality of rings 428 may be circumferentially offsetfrom the second plurality of rings 426. In such an instance, thelongitudinally extending segment 434 of the suture 416 which extendsbetween the second plurality of rings 426 and the third plurality ofrings 428 may extend at a non-orthogonal angle to the plane formed bythe third plurality of rings 428. In some cases, the longitudinallyextending segment 434 may include rings in place of or in addition tothe rings 424, 426, 428 at the suture loops 418.

The second end 422 of the suture 416 may be passed through the openingin the first ring 428 a. The suture 416 may then be directed towards andthrough the opening in the second ring 426 b (e.g., in a directionopposite the second suture loop 418 b, although this is not required).The suture 416 may then be directed from the second ring 428 b towardsand through the third ring 428 c. The suture 416 may then be passed andcoupled to the first ring 428 a to form the third suture loop 418 c. Asdescribed above, the third plurality of rings 428 may be fixedly coupledto the stent frame 402 such that the suture 416 is not required to beinterwoven with the stent frame 402 in order to manipulate the stentframe 402 adjacent to the third plurality of rings 428.

To collapse, reposition, or reshape the implant 400, the suture 416 maybe gripped at any location between the first end 420 and the second end422 or at any of the rings 424, 426, 428 and pulled or otherwiseactuated in a proximal direction. In some cases, the suture 416 may beprovided with extra length or slack to allow the suture 416 to begripped easier. In some cases, the extra length may be most apparent inthe longitudinally extending segments 432, 434. In other embodiments,the suture 416 may be actuated in a distal direction. It is contemplatedthat the direction of actuation (e.g., proximal or distal) required toactuate the suture 416 may be dependent on the direction in which thesuture 416 is interwoven with the stent frame 402. As suture 416 isactuated, the suture loops 418 begin to constrain or reduce the diameter(not explicitly shown) of the implant 400. The suture loop 418, 418 b,418 c which constrains first may be dependent on where the suture 416 isgripped. For example, the suture loop 418 closest to the grip locationmay constrain first. Continued actuation of the suture 416 may cause thesuture loops 418 further from the grip location to constrain or reducein diameter.

FIG. 11 illustrates a side view of an illustrative endoluminal implantor stent 500. In some instances, the stent 500 may be formed from anelongated tubular stent frame 502. While the stent 500 is described asgenerally tubular, it is contemplated that the stent 500 may take anycross-sectional shape desired. The stent 500 may have a first, orproximal end 504, a second, or distal end 506, and an intermediateregion 508 disposed between the first end 504 and the second end 506.The stent 500 may include a lumen 510 extending from a first openingadjacent the first end 504 to a second opening adjacent to the secondend 506 to allow for the passage of food, fluids, etc.

The stent 500 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 500 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 500 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 502 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 502 may be braidedwith one filament. In other embodiments, the stent frame 502 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 502 maybe knitted, such as the ULTRAFLEX™ stents made by Boston ScientificCorp. In yet another embodiment, the stent frame 502 may be of a knottedtype, such the PRECISION COLONIC™ stents made by Boston Scientific Corp.In still another embodiment, the stent frame 502 may be laser cut, suchas the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 500 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys, and/or polymers, as desired, enabling the stent 500to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 500 tobe removed with relative ease as well. For example, the stent 500 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 500 maybe self-expanding (i.e., configured to automatically radially expandwhen unconstrained). In some embodiments, fibers may be used to make thestent 500, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 500 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 500 maybe self-expanding while in other embodiments, the stent 500 may beexpand by an expansion device (such as, but not limited to a ballooninserted within the lumen 510 of the stent 500). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 500 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 510 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 500may include a first end region 512 proximate the proximal end 504 and asecond end region 514 proximate the second end 506. In some embodiments,the first end region 512 and the second end region 514 may includeretention features or anti-migration flared regions (not explicitlyshown at the second end region 514) having enlarged diameters relativeto the intermediate portion 508. The anti-migration flared regions,which may be positioned adjacent to the first end 504 and the second end506 of the stent 500, may be configured to engage an interior portion ofthe walls of the esophagus, stomach or other body lumen. In someembodiments, the retention features, or flared regions may have a largerdiameter than the cylindrical intermediate region 508 of the stent 500to prevent the stent 500 from migrating once placed in the esophagus,stomach, or other body lumen. It is contemplated that a transition fromthe cross-sectional area of the intermediate region 508 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 500 mayhave a uniform diameter from the proximal end 504 to the distal end 506.

It is contemplated that the stent 500 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 500to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 500 tobe removed with relative ease as well. For example, the stent 500 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 500 maybe self-expanding or require an external force to expand the stent 500.In some embodiments, composite filaments may be used to make the stent500, which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 500 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 500, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 500, or portions thereof, may be biostable.

The implant 500 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 500, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 500 may further include a suture 516. The suture 516 may beformed as a part of the stent frame 502. For example, the suture 516 maybe braided with, knitted with, or otherwise included in the stent frame502 during the manufacture of the stent 500. In other words, one or moreof the filaments of the stent frame 502 may be replaced with a suture516. The suture 516 may be formed from a material having differentmechanical properties from the remainder of the stent frame 502. Forexample, the suture 516 may be more elastic than the remainder of thestent frame 502. The suture 516 may be formed with the stent frame 502such that it has some extra length or slack. This may allow the suture516 to sag or protrude into the lumen 510 of the stent to allow thesuture 516 to be more apparent to the physician.

To collapse, reposition, or reshape the implant 500, the suture 516 maybe gripped at any location between the first end 504 and the second end506 of the stent 500 and pulled or otherwise actuated in a proximaldirection. In other embodiments, the suture 516 may be actuated in adistal direction. It is contemplated that the direction of actuation(e.g., proximal or distal) required to actuate the suture 516 may bedependent on the direction in which the suture 516 is wound or knittedwith the stent frame 502. As suture 516 is actuated, the suture 516 maycontract the stent frame 502 axially and circumferentially begin toconstrain or reduce the diameter (not explicitly shown) of the implant500. The portion of the stent frame 502 which constrains first may bedependent on where the suture 516 is gripped. For example, the stentframe 502 closest to the grip location may constrain first. Continuedactuation of the suture 516 may cause the stent frame 502 further fromthe grip location to constrain or reduce in diameter.

FIG. 11 illustrates a side view of an illustrative endoluminal implantor stent 600. In some instances, the stent 600 may be formed from anelongated tubular stent frame 602. While the stent 600 is described asgenerally tubular, it is contemplated that the stent 600 may take anycross-sectional shape desired. The stent 600 may have a first, orproximal end 604, a second, or distal end 606, and an intermediateregion 608 disposed between the first end 604 and the second end 606.The stent 600 may include a lumen 610 extending from a first openingadjacent the first end 604 to a second opening adjacent to the secondend 606 to allow for the passage of food, fluids, etc.

The stent 600 may be expandable from a first radially collapsedconfiguration (not explicitly shown) to a second radially expandedconfiguration. In some cases, the stent 600 may be deployed to aconfiguration between the collapsed configuration and a fully expandedconfiguration. The stent 600 may be structured to extend across astricture and to apply a radially outward pressure to the stricture in alumen to open the lumen and allow for the passage of foods, fluids, air,etc.

The stent frame 602 may have a woven structure, fabricated from a numberof filaments. In some embodiments, the stent frame 602 may be braidedwith one filament. In other embodiments, the stent frame 602 may bebraided with several filaments, as is found, for example, in theWALLFLEX®, WALLSTENT®, and POLYFLEX® stents, made and distributed byBoston Scientific Corp. In another embodiment, the stent frame 602 maybe knitted, such as the ULTRAFLEX™ stents made by Boston ScientificCorp. In yet another embodiment, the stent frame 602 may be of a knottedtype, such the PRECISION COLONIC™ stents made by Boston Scientific Corp.In still another embodiment, the stent frame 602 may be laser cut, suchas the EPIC™ stents made by Boston Scientific Corp.

It is contemplated that the stent 600 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 600to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 600 tobe removed with relative ease as well. For example, the stent 600 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 600 maybe self-expanding (i.e., configured to automatically radially expandwhen unconstrained). In some embodiments, fibers may be used to make thestent 600, which may be composite fibers, for example, having an outershell made of Nitinol having a platinum core. It is further contemplatedthe stent 600 may be formed from polymers including, but not limited to,polyethylene terephthalate (PET). In some embodiments, the stent 600 maybe self-expanding while in other embodiments, the stent 600 may beexpand by an expansion device (such as, but not limited to a ballooninserted within the lumen 610 of the stent 600). As used herein the term“self-expanding” refers to the tendency of the stent to return to apreprogrammed diameter when unrestrained from an external biasing force(for example, but not limited to a delivery catheter or sheath). Thestent 600 may include a one-way valve, such as an elastomeric slit valveor duck bill valve, positioned within the lumen 610 thereof to preventretrograde flow of gastrointestinal fluids.

In some instances, in the radially expanded configuration, the stent 600may include a first end region 612 proximate the proximal end 604 and asecond end region 614 proximate the second end 606. In some embodiments,the first end region 612 and the second end region 614 may includeretention features or anti-migration flared regions (not explicitlyshown at the second end region 614) having enlarged diameters relativeto the intermediate portion 608. The anti-migration flared regions,which may be positioned adjacent to the first end 604 and the second end606 of the stent 600, may be configured to engage an interior portion ofthe walls of the esophagus, stomach or other body lumen. In someembodiments, the retention features, or flared regions may have a largerdiameter than the cylindrical intermediate region 608 of the stent 600to prevent the stent 600 from migrating once placed in the esophagus,stomach, or other body lumen. It is contemplated that a transition fromthe cross-sectional area of the intermediate region 608 to the retentionfeatures or flared regions may be gradual, sloped, or occur in an abruptstep-wise manner, as desired. In other embodiments, the stent 600 mayhave a uniform diameter from the proximal end 604 to the distal end 606.

It is contemplated that the stent 600 can be made from a number ofdifferent materials such as, but not limited to, metals, metal alloys,shape memory alloys and/or polymers, as desired, enabling the stent 600to be expanded into shape when accurately positioned within the body. Insome instances, the material may be selected to enable the stent 600 tobe removed with relative ease as well. For example, the stent 600 can beformed from alloys such as, but not limited to, Nitinol and ELGILOY®.Depending on the material selected for construction, the stent 600 maybe self-expanding or require an external force to expand the stent 600.In some embodiments, composite filaments may be used to make the stent600, which may include, for example, an outer shell or cladding made ofNitinol and a core formed of platinum or other radiopaque material. Itis further contemplated the stent 600 may be formed from polymersincluding, but not limited to, polyethylene terephthalate (PET). In someinstances, the filaments of the stent 600, or portions thereof, may bebioabsorbable or biodegradable, while in other instances the filamentsof the stent 600, or portions thereof, may be biostable.

The implant 600 may be may be entirely, substantially or partially,covered with a polymeric covering, such as a coating (not explicitlyshown). The covering may be disposed on an inner surface and/or outersurface of the implant 600, as desired. When so provided a polymericcovering may reduce or eliminate tissue ingrowth and/or reduce foodimpaction.

The implant 600 may further include a retrieval suture 616. The suture616 may include a retrieval suture loop 618 which may be configured tobe grasped by forceps or other tool during a clinical procedure forstent removal and or repositioning. In some cases, the retrieval sutureloop 618 may be formed by tying a knot 620 between, or otherwisecoupling (e.g., heat bonding, adhesive, etc.) a first end 622 and asecond end 624 of the retrieval suture. In other embodiments, theretrieval suture loop 618 may be formed at either the first end 622 orthe second end 624 of the retrieval suture 616. In such an instance, theend 622, 624 free from the retrieval suture loop 618 may be coupled tothe stent 600 or the opposing end 622, 624 of the retrieval suture 616,although this is not required.

The suture 616 may be interwoven with the stent frame 602 at intervalsalong a length of the implant 600 to create a plurality of suture loops626 a, 626 b (collectively, 626). While the illustrative implant 600 isshown and described has having two suture loops 626, it is contemplatedthat the implant 600 may include more than two suture loops 626, asdesired. For example, the implant 600 may include three, four, five, ormore suture loops 626. It is contemplated that the suture loops 626 maybe positioned at regular or even intervals throughout the overall lengthof the implant 600. However, in other embodiments, the suture loops 626may be positioned at eccentric or uneven intervals along the length ofthe implant 600, as desired. It is contemplated that the suture loops626 may be positioned to facilitate retrieval, repositioning, and/orreshaping of the stent 600. For example, in a stent 600 having two ormore flared or enlarged regions, as in the AXIOS® stent made anddistributed by Boston Scientific Corp., a first retrieval suture loop626 a may be positioned adjacent to the first flare and a secondretrieval suture loop 626 b may be positioned adjacent to the secondflare.

In some embodiments, one, two or more, or all of the suture loops 626may extend entirely around the circumference (e.g., 360°) of the stentframe 602. In other embodiments, one, two or more, or all of the sutureloops 626 may extend less than 360° about the circumference of the stentframe 602. In some embodiments, one or more of the suture loops 626 mayextend 3634° or less, 300° or less, 270° or less, 225° or less, 180° orless, 135° or less, etc. In yet other embodiments, one, two or more, orall of the suture loops may extend more than 360° about thecircumference of the stent frame 602. In the yet other embodiments, thesuture loops 626 may be positioned such that individually the loops 626a, 626 b extend less than the 360° about the circumference of the stentframe 602 but collectively extend about 360° about the circumference, asillustrated in FIG. 11.

The suture loops 626 may be formed from a single unitary suture 616. Itis contemplated that the suture 616 may be interwoven with the stentframe 602 such that segments of the suture loops 626 may be constrainedin a predetermined sequential order. In some cases, the proximal loop626 a and/or the distal loop 626 b may not extend in a continuous loop.Rather, the proximal loop 626 a and/or distal loop 626 b may be brokeninto sections by longitudinally extending interconnecting segments 638,644, 652, 660, 670, 678 which extend between the proximal loop 626 a andthe distal loop 626 b.

The suture 616 may be interwoven with the stent frame 602 by threadingone of the ends 622, 624 around the proximal end 604 of the implant 600beginning at a first circumferential location 628 and moving (e.g.,threading) in a first direction. In the illustrative example, the suture616 is described as initially being threaded in a clockwise direction.However, the reverse configuration in which the suture is initiallythreaded in a counterclockwise direction is also contemplated. Thesuture 616 may be threaded around about one sixth (e.g., 60°) of thecircumference of the implant 600 such that a first segment 630 of thesuture 616 extends between the first circumferential location 628 and asecond circumferential location 632. The first and secondcircumferential locations 628, 632 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 634 of the implant 600) from the first end 604of the implant 600. In some cases, the suture 616 may be threaded suchthat it is interwoven with the stent frame 602 such that a portion ofthe suture 616 is within the lumen 610 of the implant 600 and a portionof the suture 616 is positioned along an exterior surface of the implant600 (e.g., such that it will be in contact with a vessel lumen when theimplant 600 is deployed within the body). At the second circumferentiallocation 632, the suture 616 may be threaded along a length of implant600 in a direction towards the second end 606 such that a secondlongitudinally extending interconnecting segment 638 of the suture 616extends along a length of the implant 600 in a generally lineardirection. The length of the second segment 638 of the suture 616 mayvary depending on the application. For example, some implants 600 mayinclude radially extending quills (not explicitly shown) configured toengage a body tissue. The second segment 638 may be configured to extendalong a length equal to or greater to a length of the implant 600including the radially extending quills. This is just one example. Otherfeatures of the implant 600, such as, but not limited to, the length ofthe implant 600 may be used to determine the length of the secondsegment 638 of the suture 616.

The second segment 638 of the suture 616 may extend from the secondcircumferential location 632 to a third circumferential location 638.The second circumferential location and the third circumferentiallocation 638 may be at similar radial points about the circumference ofthe implant 600 but spaced a distance along the length thereof. At thethird circumferential location 638, a third segment 640 of the suture616 may be threaded radially about the circumference of the implant 600in the first direction (e.g., clockwise). The third segment 640 mayextend between the third circumferential location 638 and a fourthcircumferential location 642 for about one sixth (e.g., 60°) of thecircumference of the implant 600 to form a portion of the suture loop626 b.

At the fourth circumferential location 642, the suture 616 may bethreaded along a length of implant 600 in a direction towards the firstend 604 such that a fourth longitudinally extending interconnectingsegment 644 of the suture 616 extends along a length of the implant 600in a direction parallel to the longitudinal axis 634. The length of thefourth segment 644 of the suture 616 may be about the same length as thesecond segment 638 of the suture 616. The fourth segment 644 of thesuture 616 may extend between the fourth circumferential location 642and a fifth circumferential location 646. In some cases, the secondand/or fourth segments 638, 644 of the suture may not be interwoven withthe stent body 602 but rather extend along an inner or outer surface ofthe stent frame 602. In some embodiments, the first, second, and fifthcircumferential locations 628, 632, 646 may be positioned at a similarlongitudinal distance (e.g., in a direction extending generally parallelto the longitudinal axis 634 of the implant 600) from the first end 604of the implant 600.

From the fifth circumferential location 646, the suture 616 may bethreaded through the stent body 602 in the first direction (e.g., awayfrom the first segment 630) to form a fifth segment 648 of the suture616. The fifth segment 648 of the suture 616 may be threaded through thestent frame 602 to a sixth circumferential location 650. The suture 616may be threaded around about one sixth (e.g., 60°) of the circumferenceof the implant 600 to form a portion of the proximal loop 626 a.

At the sixth circumferential location 650, the suture 616 may bethreaded along a length of implant 600 in a direction towards the secondend 606 such that a sixth longitudinally extending interconnectingsegment 652 of the suture 616 extends along a length of the implant 600in a generally linear direction. The length of the sixth segment 652 ofthe suture 616 may be about the same length as the second segment 654and/or fourth segment 644 of the suture 616.

The sixth segment 652 of the suture 616 may extend from the sixthcircumferential location 650 to a seventh circumferential location 654.The sixth circumferential location 650 and the seventh circumferentiallocation 654 may be at similar radial points about the circumference ofthe implant 600 but spaced a distance along the length thereof. At theseventh circumferential location 654, a seventh segment 656 of thesuture 616 may be threaded radially about the circumference of theimplant 600 in the first direction (e.g., clockwise). The seventhsegment 656 may extend between the seventh circumferential location 654and an eighth circumferential location 658 for about one sixth (e.g.,60°) of the circumference of the implant 600 to form a portion of thesuture loop 626 b.

At the eighth circumferential location 658, the suture 616 may bethreaded along a length of implant 600 in a direction towards the firstend 604 such that an eighth longitudinally extending interconnectingsegment 660 of the suture 616 extends along a length of the implant 600in a direction parallel to the longitudinal axis 634. The length of theeighth segment 660 of the suture 616 may be about the same length as thesecond, fourth, and sixth segments 636, 644, 652 of the suture 616. Theeighth segment 660 of the suture 616 may extend between the eighthcircumferential location 658 and a ninth circumferential location 662.

From the ninth circumferential location 662, the suture 616 may bethreaded through the stent body 602 in the first direction (e.g., awayfrom the fifth segment 648) to form a ninth segment 664 of the suture616. The ninth segment 664 of the suture 616 may be threaded through thestent frame 602 to a tenth circumferential location 668. The suture 616may be threaded around about one sixth (e.g., 60°) of the circumferenceof the implant 600 to form a portion of the proximal loop 626 a.

At the tenth circumferential location 668, the suture 616 may bethreaded along a length of implant 600 in a direction towards the secondend 606 such that a tenth longitudinally extending interconnectingsegment 670 of the suture 616 extends along a length of the implant 600in a generally linear direction. The length of the tenth segment 670 ofthe suture 616 may be about the same length as the second, fourth,sixth, and eighth segments 654, 644, 652, 660 of the suture 616.

The tenth segment 670 of the suture 616 may extend from the tenthcircumferential location 668 to an eleventh circumferential location672. The tenth circumferential location 668 and the eleventhcircumferential location 672 may be at similar radial points about thecircumference of the implant 600 but spaced a distance along the lengththereof. At the eleventh circumferential location 672, an eleventhsegment 674 of the suture 616 may be threaded radially about thecircumference of the implant 600 in the first direction (e.g.,clockwise). The eleventh segment 674 may extend between the eleventhcircumferential location 672 and a twelfth circumferential location 676for about one sixth (e.g., 60°) of the circumference of the implant 600to form a portion of the suture loop 626 b.

At the twelfth circumferential location 676, the suture 616 may bethreaded along a length of implant 600 in a direction towards the firstend 604 such that a twelfth longitudinally extending interconnectingsegment 678 of the suture 616 extends along a length of the implant 600in a direction parallel to the longitudinal axis 634. The length of thetwelfth segment 678 of the suture 616 may be about the same length asthe second, fourth, sixth, eighth, and tenth segments 636, 644, 652,660, 670 of the suture 616. The twelfth segment 678 of the suture 616may extend between the twelfth circumferential location 676 and athirteenth circumferential location 680. The thirteenth circumferentiallocation 680 may be at approximately the same radial location as thefirst circumferential location 628. However, this is not required. Forexample, the first circumferential location 628 may be radially spacedfrom the thirteenth circumferential location 680 by, for example, 1° orless, 5° or less, 10° or less, 20° or less, etc. The first and secondends 620, 622 of the suture 616 may then be tied or secured as describedabove.

The proximal suture loop 626 a may be formed from circumferentiallydiscontinuous segments of the suture including the first segment 630,the fifth segment 648, and the ninth segment 664. The circumferentialpoints forming each of these segments (e.g., first, second, fifth,sixth, ninth, and tenth circumferential points 628, 632, 646, 650, 662,668) may be positioned at a similar longitudinal distance (e.g., in adirection extending generally parallel to the longitudinal axis 634 ofthe implant 600) from the first end 604 of the implant 600. The distalsuture loop 626 b may be formed from circumferentially discontinuoussegments of the suture including the third segment 640, the seventhsegment 656, and the eleventh segment 674. The circumferential pointsforming each of these segments (e.g., third, fourth, seventh, eighth,eleventh, and twelfth circumferential points 638, 642, 654, 658, 672,676) may be positioned at a similar longitudinal distance (e.g., in adirection extending generally parallel to the longitudinal axis 634 ofthe implant 600) from the first end 604 of the implant 600.

While each of the circumferentially extending segments 630, 640, 648,656, 664, 674 are described as extending approximately 60° about thecircumference of the stent frame 602, this is not required. If it isdesired for each circumferentially extending segment to be approximatelyuniform, the arc length of the circumferentially extending segment maybe dependent on the number of circumferentially extending segments. Itis further contemplated that the circumferentially extending segmentsneed not all have the same arc length.

To collapse the implant 600, the retrieval suture loop 618, or a portionof the first suture loop 626 a in the absence of the retrieval sutureloop 618, may be pulled or otherwise actuated in a proximal direction.It is contemplated that the direction of actuation (e.g., proximal ordistal) required to actuate the suture 616 may be dependent on thedirection in which the suture 616 is interwoven with the stent frame602. As the retrieval suture loop 618, or the first suture loop 626 a inthe absence of the retrieval suture loop 618, is actuated, the sutureloops 626 begin to constrain or reduce the diameter of the implant 600.The orientation of the suture loops 626 may cause the suture loops 626to constrain at substantially the same time. However, opposing sides ofthe proximal suture loop 626 a and the distal suture loop 626 b mayconstrain first.

The materials that can be used for the various components of theimplants 10, 100, 200, (and variations, systems or components thereofdisclosed herein) and the various elements thereof disclosed herein mayinclude those commonly associated with medical devices. For simplicitypurposes, the following discussion makes reference to the implants 10,100, 200 (and variations, systems or components disclosed herein).However, this is not intended to limit the devices and methods describedherein, as the discussion may be applied to other elements, members,components, or devices disclosed herein.

The implants 10, 100, 200 may be made from a metal, metal alloy, polymer(some examples of which are disclosed below), a metal-polymer composite,ceramics, combinations thereof, and the like, or other suitablematerial. Some examples of suitable metals and metal alloys includestainless steel, such as 304V, 304L, and 316LV stainless steel; mildsteel; nickel-titanium alloy such as linear-elastic and/or super-elasticnitinol; other nickel alloys such as nickel-chromium-molybdenum alloys(e.g., UNS: N06625 such as INCONEL® 625, UNS: N06022 such as HASTELLOY®C-22®, UNS: N10276 such as HASTELLOY® C276®, other HASTELLOY® alloys,and the like), nickel-copper alloys (e.g., UNS: N04400 such as MONEL®400, NICKELVAC® 400, NICORROS® 400, and the like),nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035 such asMP35-N® and the like), nickel-molybdenum alloys (e.g., UNS: N10665 suchas HASTELLOY® ALLOY B2®), other nickel-chromium alloys, othernickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-ironalloys, other nickel-copper alloys, other nickel-tungsten or tungstenalloys, and the like; cobalt-chromium alloys; cobalt-chromium-molybdenumalloys (e.g., UNS: R30003 such as ELGILOY®, PHYNOX®, and the like);platinum enriched stainless steel; titanium; combinations thereof; andthe like; or any other suitable material.

As alluded to herein, within the family of commercially availablenickel-titanium or nitinol alloys, is a category designated “linearelastic” or “non-super-elastic” which, although may be similar inchemistry to conventional shape memory and super elastic varieties, mayexhibit distinct and useful mechanical properties. Linear elastic and/ornon-super-elastic nitinol may be distinguished from super elasticnitinol in that the linear elastic and/or non-super-elastic nitinol doesnot display a substantial “superelastic plateau” or “flag region” in itsstress/strain curve like super elastic nitinol does. Instead, in thelinear elastic and/or non-super-elastic nitinol, as recoverable strainincreases, the stress continues to increase in a substantially linear,or a somewhat, but not necessarily entirely linear relationship untilplastic deformation begins or at least in a relationship that is morelinear that the super elastic plateau and/or flag region that may beseen with super elastic nitinol. Thus, for the purposes of thisdisclosure linear elastic and/or non-super-elastic nitinol may also betermed “substantially” linear elastic and/or non-super-elastic nitinol.

In some cases, linear elastic and/or non-super-elastic nitinol may alsobe distinguishable from super elastic nitinol in that linear elasticand/or non-super-elastic nitinol may accept up to about 2-5% strainwhile remaining substantially elastic (e.g., before plasticallydeforming) whereas super elastic nitinol may accept up to about 8%strain before plastically deforming. Both of these materials can bedistinguished from other linear elastic materials such as stainlesssteel (that can also can be distinguished based on its composition),which may accept only about 0.2 to 0.44 percent strain beforeplastically deforming.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy is an alloy that does not show anymartensite/austenite phase changes that are detectable by differentialscanning calorimetry (DSC) and dynamic metal thermal analysis (DMTA)analysis over a large temperature range. For example, in someembodiments, there may be no martensite/austenite phase changesdetectable by DSC and DMTA analysis in the range of about −60 degreesCelsius (° C.) to about 120° C. in the linear elastic and/ornon-super-elastic nickel-titanium alloy. The mechanical bendingproperties of such material may therefore be generally inert to theeffect of temperature over this very broad range of temperature. In someembodiments, the mechanical bending properties of the linear elasticand/or non-super-elastic nickel-titanium alloy at ambient or roomtemperature are substantially the same as the mechanical properties atbody temperature, for example, in that they do not display asuper-elastic plateau and/or flag region. In other words, across a broadtemperature range, the linear elastic and/or non-super-elasticnickel-titanium alloy maintains its linear elastic and/ornon-super-elastic characteristics and/or properties.

In some embodiments, the linear elastic and/or non-super-elasticnickel-titanium alloy may be in the range of about 50 to about 60 weightpercent nickel, with the remainder being essentially titanium. In someembodiments, the composition is in the range of about 54 to about 57weight percent nickel. One example of a suitable nickel-titanium alloyis FHP-NT alloy commercially available from Furukawa Techno Material Co.of Kanagawa, Japan. Some examples of nickel titanium alloys aredisclosed in U.S. Pat. Nos. 5,238,004 and 6,508,803, which areincorporated herein by reference. Other suitable materials may includeULTANIUM™ (available from Neo-Metrics) and GUM METAL™ (available fromToyota). In some other embodiments, a superelastic alloy, for example asuperelastic nitinol can be used to achieve desired properties.

In at least some embodiments, portions or all of implants 10, 100, 200may also be doped with, made of, or otherwise include a radiopaquematerial. Radiopaque materials are generally understood to be materialswhich are opaque to RF energy in the wavelength range spanning x-ray togamma-ray (at thicknesses of <0.005″). These materials are capable ofproducing a relatively dark image on a fluoroscopy screen relative tothe light image that non-radiopaque materials such as tissue produce.This relatively bright image aids the user of implants 10, 100, 200 indetermining its location. Some examples of radiopaque materials caninclude, but are not limited to, gold, platinum, palladium, tantalum,tungsten alloy, polymer material loaded with a radiopaque filler, andthe like. Additionally, other radiopaque marker bands and/or coils mayalso be incorporated into the design of implants 10, 100, 200 to achievethe same result.

In some embodiments, a degree of Magnetic Resonance Imaging (MRI)compatibility is imparted into implants 10, 100, 200. For example,implants 10, 100, 200 or portions thereof, may be made of a materialthat does not substantially distort the image and create substantialartifacts (i.e., gaps in the image). Certain ferromagnetic materials,for example, may not be suitable because they may create artifacts in anMRI image. The implants 10, 100, 200 or portions thereof, may also bemade from a material that the MRI machine can image. Some materials thatexhibit these characteristics include, for example, tungsten,cobalt-chromium-molybdenum alloys (e.g., UNS: R30003 such as ELGILOY®,PHYNOX®, and the like), nickel-cobalt-chromium-molybdenum alloys (e.g.,UNS: R30035 such as MP35-N® and the like), nitinol, and the like, andothers.

Some examples of suitable polymers for implants 10, 100, 200 may includepolytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE),fluorinated ethylene propylene (FEP), polyoxymethylene (POM, forexample, DELRIN® available from DuPont), polyether block ester,polyurethane (for example, Polyurethane 85A), polypropylene (PP),polyvinylchloride (PVC), polyether-ester (for example, ARNITEL®available from DSM Engineering Plastics), ether or ester basedcopolymers (for example, butylene/poly(alkylene ether) phthalate and/orother polyester elastomers such as HYTREL® available from DuPont),polyamide (for example, DURETHAN® available from Bayer or CRISTAMID®available from Elf Atochem), elastomeric polyamides, blockpolyamide/ethers, polyether block amide (PEBA, for example availableunder the trade name PEBAX®), ethylene vinyl acetate copolymers (EVA),silicones, polyethylene (PE), MARLEX® high-density polyethylene, MARLEX®low-density polyethylene, linear low density polyethylene (for exampleREXELL®), polyester, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET), polytrimethylene terephthalate, polyethylenenaphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI),polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene oxide(PPO), poly paraphenylene terephthalamide (for example, KEVLAR®),polysulfone, nylon, nylon-12 (such as GRILAMID® available from EMSAmerican Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene vinylalcohol, polyolefin, polystyrene, epoxy, polyvinylidene chloride (PVdC),poly(styrene-b-isobutylene-b-styrene) (for example, SIBS and/or SIBS50A), polycarbonates, ionomers, biocompatible polymers, other suitablematerials, or mixtures, combinations, copolymers thereof, polymer/metalcomposites, and the like.

Those skilled in the art will appreciate that the different embodimentsof the implant described here, their mode of operation, etc., are merelyrepresentative of the environment in which the present disclosureoperates. Accordingly, a variety of alternatively shaped collaboratingcomponents may also be used as a substitutive for the purpose ofengaging, steering and locating the stent at a desired target site,thus, not limiting the scope of the present disclosure. Further, thedisclosed implants may be adequately stretchable, extendable, andretractable, allowing for its flexible deployment. More particularly,the configurations described here may be applicable for other medicalapplications as well, and accordingly, a variety of other medicaldevices may be used in combination with the implant. Those medicaldevices may include biopsy forceps, scissors, lithotripters, dilators,other cautery tools, and the like.

Further, while the implant is generally described along with anexemplary rigid and flexible region(s), a variety of otherconfigurations and arrangements may also be contemplated and conceivedas well. In addition, the operations, devices, and components, describedherein may be equally applicable for other purposes where a component isrequired to be positioned in places where a leakage needs to be avoidedor other treatments are desired. Embodiments of the present disclosureare thus applicable to medical and/or non-medical environments. Further,certain aspects of the aforementioned embodiments may be selectivelyused in collaboration, or removed, during practice, without departingfrom the scope of the disclosed embodiments.

Those skilled in the art will recognize that the present invention maybe manifested in a variety of forms other than the specific embodimentsdescribed and contemplated herein. Accordingly, departure in form anddetail may be made without departing from the scope and spirit of thepresent disclosure as described in the appended claims.

What is claimed is:
 1. An implant, the implant comprising: an elongatedtubular member comprising: a stent having a proximal end region, adistal end region, and a circumference; a retrieval suture interwovenwith the stent, the retrieval suture including a first suture loopextending circumferentially around the stent and adjacent to a sutureretrieval loop and a second suture loop extending circumferentiallyaround the stent and longitudinally spaced from the first suture loop,the first and second suture loops coupled via one or moreinterconnecting longitudinal segments; wherein at least one of the firstor second suture loops has an arc length of 270° or less of thecircumference of the stent; and wherein the first suture loop is adiscontinuous loop comprising two or more circumferential segments ofthe retrieval suture separated by the one or more interconnectinglongitudinal segments.
 2. The implant of claim 1, wherein the at leastone of the first or second suture loops has an arc length of 180° orless of the circumference of the stent.
 3. The implant of claim 1,wherein the retrieval suture is a single unitary structure.
 4. Theimplant of claim 1, wherein the stent includes a first outer diameteradjacent the proximal end region and a second smaller outer diameteradjacent the distal end region.
 5. The implant of claim 4, wherein thefirst suture loop is positioned adjacent to the proximal end region andthe second suture loop is positioned adjacent to the distal end region.6. The implant of claim 1, wherein a force exerted on the sutureretrieval loop is configured to partially collapse the stent adjacent tothe second suture loop.
 7. The implant of claim 6, wherein once an outerdiameter of the stent adjacent to the second suture loop is at leastpartially collapsed, the force exerted on the suture retrieval loop isconfigured to collapse the stent adjacent to the first suture loop. 8.The implant of claim 1, wherein the retrieval suture further comprises athird suture loop extending circumferentially around the stent andlongitudinally spaced from the second suture loop, the second and thirdsuture loops coupled via one or more interconnecting segments.
 9. Theimplant of claim 1, wherein the elongated tubular member furthercomprises a flexible sleeve extending distally from the distal endregion of the stent.
 10. The implant of claim 9, wherein the retrievalsuture further comprises a third suture loop extending about acircumference of the flexible sleeve and longitudinally spaced from thesecond suture loop, the second and third suture loops coupled via one ormore interconnecting segments.
 11. The implant of claim 10, wherein aforce exerted on the retrieval suture loop is configured to partiallycollapse the flexible sleeve adjacent to the third suture loop.
 12. Theimplant of claim 11, wherein once an outer diameter of the flexiblesleeve adjacent to the third suture loop is at least partiallycollapsed, the force exerted on the retrieval suture loop is configuredto sequentially collapse the stent adjacent to the second suture loopfollowed by the stent adjacent to the first suture loop.
 13. An implant,the implant comprising: an elongated tubular member comprising: a stenthaving a proximal end and a distal end; a retrieval suture interwovenwith the stent, the retrieval suture comprising: a first segmentextending circumferentially between a first circumferential location anda second circumferential location; a second segment extendinglongitudinally between the second circumferential location and a thirdcircumferential location; a third segment extending circumferentiallybetween the third circumferential location and a fourth circumferentiallocation and interwoven with the stent; a fourth segment extendinglongitudinally between the fourth circumferential location and a fifthcircumferential location; and a fifth segment extendingcircumferentially between the fifth circumferential location and a sixthcircumferential location; wherein the first, second, fifth, and sixthcircumferential locations are at a first longitudinal distance from theproximal end of the stent and the third and fourth circumferentiallocations are at a second longitudinal distance, different from thefirst longitudinal distance, from the proximal end of the stent; andwherein the first and fifth segments together form a discontinuous firstsuture loop and the third segment forms a second suture loop; andwherein at least one of the first or second suture loops has an arclength of 270° or less of a circumference of the stent.
 14. The implantof claim 13, wherein the at least one of the first or second sutureloops has an arc length of 180° or less of the circumference of thestent.
 15. The implant of claim 13, wherein the retrieval suture is asingle unitary structure.
 16. An implant, the implant comprising: anelongated tubular member comprising: a stent having a proximal endregion and a distal end region, the stent including a first outerdiameter adjacent the proximal end region and a second smaller outerdiameter adjacent the distal end region; a flexible sleeve extendingdistally from the distal end region of the stent; a retrieval sutureinterwoven with the stent, the retrieval suture including a first sutureloop extending about a circumference of the stent and adjacent to asuture retrieval loop, a second suture loop extending about thecircumference of the stent and longitudinally spaced from the firstsuture loop, and a third suture loop extending about a circumference ofthe flexible sleeve and longitudinally spaced from the second sutureloop, the first and second suture loops coupled via one or moreinterconnecting segments and the second and third suture loops coupledvia one or more interconnecting segments; wherein at least one of thefirst, second, or third suture loops has an arc length of 270° or lessof the circumference of the stent.
 17. The implant of claim 16, whereinthe at least one of the first, second, or third suture loops has an arclength of 180° or less of the circumference of the stent.
 18. Theimplant of claim 16, wherein the retrieval suture is a single unitarystructure.
 19. The implant of claim 16, wherein the first suture loopand the second suture loop are each formed of discontinuous segments.